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The genes for MHC class II regulatory factors RFX1 and RFX2 are located on the short arm of chromosome 19
SHORT COMMUNICATION The Genes for MHC Class II Regulatory Factors RFXI and RFX2 Are Located on the Short Arm of Chromosome 19 L. PUGLIATTI,* 1. DERRi, t R. BERGER,t C. UCLA,* W. REITH,* AND B. MACH* *lea&et Laboratory of Molecular Genetics, Department of Genetics and Microbiology, University of Geneva Medical School, Geneva, Switzerland; and tlnstitute for Molecular Genetics, Unit INSERM301, Paris, France Received August 5, 1991; revised February 11, 1992
RFXl is a transacting DNA-binding regulatory factor involved in the control of MHC class II gene expression. RFX2 is a structurally very similar protein with identical DNA binding features. A member of the family of RFX factors is affected in an autosomal recessive disease, MHC class II deficient combined immunodeficiency (CID), caused by a defect in a trcme-acting regulatory factor controlling MHC class II gene expression. In situ hybriciation with sH-labeled RFXl cDNA has allowed us to identify two distinct targets on the short arm of chromosome 19 (19~13.1 and 19p13.2-~13.3). With the use of biotinylated genomic cosmid clones specific for RFXl and RFXB, respectively,‘it was then possible to localize RFXl at 19~13.1 and RFX2 at 19p13.2-~13.3. These two regulatory genes are thus assigned to a region of high gene density and RFXl is close to another DNA-binding factor, LYLl. Q 1992 Academic F’mm, Inc.
The three forms of human MHC class II molecules, HLA-DR, -DQ, and -DP, are encoded by closely linked and homologous cyand fi chain genes, located in the centromeric portion of the MHC, on the short arm of chromosome 6. Class II molecules are involved in the presentation of antigens to T lymphocytes, and the highly specific regulation of expression of class II genes is thus directly relevant to the control of the immune response. A form of hereditary immunodeficiency, HLA class II deficient combined immunodeficiency (CID), is characterized by a lack of expression of HLA class II genes (7). It was shown to be an autosomal recessive disease and to result from a defect in a tram-acting regulatory factor (4,s The expression of HLA class II genes is controlled primarily by c&acting DNA motifs located within the 150 bp upstream of the genes and in particular by two highly conserved sequences, the X and the Y boxes. Several protein factors have been shown to bind to these &-acting sequences and to have very specific contact points on the DNA. Figure 1 is a schematic representation of an HLA class II promoter, with certain of these protein factors [see reviews in Refs. (1,9,12)]. The case of factor RFX is of special interest since a specific defect in the binding of RFX to its target DNA sequence has been observed in patients with HLA class II deficient combined immunodeficiency (14). Following the cloning 1307
of RFX (14), it was possible to show that overexpression of RFX in transfected cells does indeed transactivate an HLA class II promoter (in preparation) and that antisense RNA expressed in transfected cells does inhibit the expression of HLA-DR genes in these cells (16). RFX is therefore a functionally relevant regulator of MHC class II gene expression. Recently, a second gene, encoding a second form of RFX, has been isolated and shown to have identical DNA-binding characteristics (unpublished). The genes corresponding to these two highly related forms of RFX are referred to as RFXl and RFXZ. In situ hybridization was performed according to Mattei et ~2. (9) on chromosome spreads obtained from phytohemagglutinin-stimulated peripheral blood lymphocyte cultures from three normal male donors. The first probe was a 1.6-kb DNA fragment derived from the RFXl cDNA clone (nucleotides 557-1899) (16), labeled by nick translation with 3H to a specific activity of O.&J1.5 X lo6 cpm/pg. After autoradiography, the preparations were stained with Giemsa for counting grains, and R and G bands were then obtained using the fluorochrome-photolysis-Giemsa (FPG) technique (9). Metaphases with 46 chromosomes and no more than 5 grains were selected for analysis. A total of 109 autoradiographic grains were scored in 52 metaphase chromosome spreads. This revealed a clustering of grains (34%) on the short arm of chromosome 19, as shown in Fig. 2A. The remaining grains were scattered more or less evenly over all the chromosomes (Fig. 2A). A small increase in grain number was noted on the long arm of chromosome 9. Three metaphases showed label on both chromosomes CLONED TRANSACTING
FACTORS
NF-YA/NF-YB
W
OCTl ocr2
CRE ‘X-ACTING
FIG. 1. Schematic representation the HLA DRA promoter.
SEQUENCES
of the factors known to bind to CENOMICS
13, 1307-1310 (19%) o&388-7543/92 $5.00
Copyright 0 1992 by Academic Press, Inc. All rights of reproduction in any form reserved.
1308
SHORT
COMMUNICATION
A Number of grains 10 8
q 1 132 133
134
19
FIG. 2. Localization of the RFXl and RFX2 genes on 19p. (A) Histogram of the distribution of grains in 52 metaphases, obtained after in situ hybridization with an 3H-labeled RFX-1 probe. The majority of grains is located on the short arm of the chromosome 19. (9) Distribution of silver grains on 29 selected chromosomes 19. The majority is on 19p13.1 and on ~13.3. (C) Hybridization with biotinylated cosmid probes for RFXl and RFXB. Examples of hybridization patterns observed on chromosome 19 for RFXl (C24) and RFX2 (C8).
19. The RFXl gene is thus localized on the short arm of chromosome 19. The localization of the RFXl gene within the short arm of chromosome 19 was then analyzed with metaphases selected for chromosome length, 12 with G banding and 17 with R banding (6). The 31 grains examined had the distribution shown in Fig. 2B, with signals over 19p13.1 and 19p13.2 and 3. Two cosmid clones containing about 30 kb of genomic DNA, isolated from a human cosmid library (17), were shown to correspond to the genes for RFXl (cosmid C24) and RFX2 (cosmid C8) (Ucla et al., in preparation). In the portion encoding the DNA-binding domain and the dimerization domains, the amino acid sequences of RFXl and RFX2 show more than 90 and 85% homology, respectively, and the two recombinant proteins can bind the X box as homo- or heterodimers (in preparation). These two cosmid probes were labeled with bio-ll-
dUTP (Sigma) by nick translation and were then prepared according to Cherif et al. (3). Competitive in situ hybridization and in situ hybridization were performed according to Cherif et al. (3). For each probe, concentrations of 1 @g/ml, 500 rig/ml, and 250 rig/ml were used in the hybridization mixture. The hybridization signal was revealed by avidin-conjugated fluorescein isothiocyanate (FITC) and amplified with additional layers of biotinylated goat anti-avidin antibody as previously described (13). R bands were obtained according to Cherif et al. (3). The slides were screened with a Zeiss fluorescence microscope equipped with filter No. 487709. With cosmid C24 as probe (RFXl), a spot on both chromatids was present in 16 metaphases on 19p13.1 on both chromosomes 19. With cosmid C8 as probe (RFX2), hybridization signals were localized as double spots on sister chromatids on 19p13.3 on both chromosomes 19 in 39
SHORT
1309
COMMUNICATION
metaphases and on only one chromosome in 3 metaphases (data not shown). These spots were very close to 19p13.2. In the metaphases with elongated chromosomes, the localization was 191313.31. Figure 2C confirms the distinct position of the two genes on p19. From these data, we conclude that RFXl is located on 19p13.1, while RFX2 is located on the same chromosome at position p13.2-~13.3. The two types of probes used in this study have different characteristics. The RFXl cDNA probe (1.6 kb) is known to hybridize to both RFXl and RFXB. This cross-hybridization is due to regions of extensive sequence homology in the coding portion of RFXl and RFX2 (16; Ucla et al., in preparation). The two cosmid clones, on the other hand, contain about 30 kb of genomic DNA and represent probes specific for each of the two genes. Only a very small portion of these sequences is represented by exons from RFXl or RFXS, and these two probes are thus not expected to cross-hybridize significantly under the experimental conditions used. Hybridization with biotin-labeled genomic cosmid clones corresponding to the RFXl and RFX2 genes confirmed the localization of these two RFX genes to 19p13 and they positioned RFXl at 19p13.1 and RFX2 at a more distal position on the same chromosome, 19p13.3 or 19p13.2-p13.3. The discrimination between the position of RFXl and RFX2 was confirmed in several metaphases and several examples are shown in Fig. 2C. Chromosome 19 has been extensively mapped. It has been suggested that it is unusual in having a higher “gene density” than other human chromosomes (10). The position of the RFXl gene indicates that it is close to LYLl, a gene that also encodes a DNA-binding transcription factor (11). Other genes known to map to this chromosomal region include MEL, JUNB, JUND, RAB3A, and EPOR (B. Trask, personal communication). The cloned RFXl and RFX2 genes will therefore contribute to the fine map of the short arm of chromosome 19. In particular, they are now used to position the RFX genes on the cosmid contig maps being developed at the Lawrence Livermore National Laboratory. RFXl has been well characterized structurally and functionally. It behaves as a transactivator of the HLADR promoter in transfection experiments, and expression of antisense RFXl RNA inhibits the expression of HLA-DR (16, and unpublished data). RFXl is therefore a trans-acting regulatory factor of MHC class II gene expression. The RFX2 gene, however, has not yet been studied functionally. The deduced RFX2 protein is almost identical to RFXl over certain functionally relevant portions of the molecule, including the DNA-binding and dimerization domains (in preparation). The recent discovery of yet a third RFX-related cDNA suggests the existence of a novel family of X box-binding factors that probably all exhibit the same DNA-binding properties to the X box of MHC class II promoters. The elucidation of their individual role in the control of MHC class II expression will represent a major chal-
lenge. HLA class II deficient combined immunodeficiency is a rare autosomal recessive disease characterized by an absence of HLA class II expression (7). It was shown to result from a defect in a tram-acting regulatory factor that is unlinked to the MHC and controls MHC class II gene expression (4). The molecular defect in this disease was then identified as an absence of binding of a DNA-binding factor specific for the X box motif of HLA class II promoters (14). Class II deficient CID thus represents the first disease attributed to a defect in a DNAbinding regulatory factor. It is not yet established whether the genetic defect in this disease concerns RFXl, RFXB, or another member of this novel family of related MHC class II X box-binding factors. The recent cloning of RFX2 and of additional members of this family should permit a systematic study of the X box-binding factor, or factors, implicated in this disorder.
ACKNOWLEDGMENTS Work was supported by grants from the Swiss National Science Foundation, the Jeantet Foundation and from the French Ministry of Researchand Technology (Grant MRT 89CO878). We are grateful to Dr. M. G. Mattei and Ms. E. Passage in Marseilles laux and Dr. F. Apiou in Paris for helpful advice tion.
and Dr. B. Dutrilon in situ hybridiza-
REFERENCES 1.
Benoist, patibility alphabet.
2.
Camargo, M., and Cervenka, replication in synchronized and replication model. Am.
3.
Cherif, D., Julier, C., Delattre, O., Derre, J., Lathrop, G. M., and Berger, R. (1990). Simultaneous localization of cosmids and chromosome R-banding by fluorescence microscopy: Application to regional mapping of human chromosome 11. Proc. Natl. Acad. Sci. USA 87: 6639-6643.
4.
de Preval, C., Lisowska-Grospierre, B., Loche, M., Griscelli, C., and Mach, B. (1985). A transacting class II regulatory gene unlinked to the MHC controls expression of HLA class II genes. Nature 318: 291-293.
5.
de P&al, C., Hadam, M. R., and Mach, genes for HLA class II antigens in cell severe combined immunodeficiency. N. 1300. Dutrillaux, B., Couturier, J., Richer, Pequignot, E. (1976). Sequence of DNA Q-bands of human chromosomes using mosoma 58: 51-61.
6.
7.
8. 9.
C., and Mathis, D. (1990). Regulation of major histocomcomplex class-II genes: X, Y and other letters of the Annu. Reu. Zmmunol. 8: 681-715. J. (1980). Pattern of chromosomal lymphocytes. II. Replication map J. Hum. Genet. 34: 757-780.
B. (1988). Regulation of lines from patients with Engl. J. Med. 318: 1295C.-L., and Viegasreplication in 277 R- and a BrdU treatment. Chro-
Griscelli, C., Lisowska-Grospierre, B., and Mach, B. (1989). Combined immunodeficiency with defective expression in MHC class II genes. Zmmunodeficiency Reu. 1: 135-153. Kara, C. J., and Glimcher, L. H. (1991). Regulation of MHC class II gene transcription. Current Op. Zmmunol. 3: 16-21. Mattei, M. G., Philip, N., Passage, E., Moisan, J. P., Mandel, J. L., and Mattei, J. F. (1985). DNA probe localization at 18~113 band by in situ hybridization and identification of a small supernumerary chromosome. Hum. Genet. 69: 268-271.
1310
SHORT
10.
McKusick, V. A. (1991). genes. FASEB J. 5: 12-20.
11.
Mellentin, J. D., Smith, S. D., and Cleary, M. L. (1989). 1~1-1, a novel gene altered by chromosomal translocation in T cell leukemia, codes for a protein with a helix-loop-helix DNA binding motivf. Cell 58: 77-83.
12.
Current
Peterlin, B. M., Anderson, G., (1990). Transcriptional regulation munol. Res. 9: 1644177.
trends
Lotscher, of HLA
in mapping
COMMUNICATION human
E., and Tsang, class II genes.
J. W. (1986). fluorescence
S., Zm-
13.
Pinkel, D., Straube, T., and Gray, analysis using quantitative high Proc. Natl. Acad. Sci. 83: 2934-2938.
14.
Reith, W., Satola, S., Herrero Sanchez, C., Amaldi, I., LisowskaGrospierre, B., Griscelli, C., Hadam, M. R., and Mach, B. (1988).
Congenital immunodeficiency with a regulatory class II gene expression lacks a specific HLA-DR ing protein, RF-X. Cell 53: 897-906.
defect in MHC promoter bind-
15.
Reith, W., Barras, Sanchez, C., and promoter binding II gene regulation.
16.
Reith, W., Herrero-Sanchez, C., Kobr, M., Silacci, P., Berte, Ch., Barras, E., Fey, S., and Mach, B. (1990). MHC class II regulatory factor RFX has a novel DNA-binding domain. Genes Deu. 4: 15281540.
17.
Rollini, P., Mach, HlA-DR b-chain Proc. Natl. Acad.
Cytogenetics hybridization.
E., Satola, S., Kobr, M., Reinharz, D., Herrero Mach, B. (1989). Cloning of the MHC class II protein affected in a hereditary defect in class hoc. Natl. Acad. Sci. USA 86: 4200-4204.
B., and Gorski, J. (1985). Linkage map of three genes: Evidence for a recent duplication event. Sci. USA 82: 7197-7201.
RFXl is a transacting DNA-binding regulatory factor involved in the control of MHC class II gene expression. RFX2 is a structurally very similar protein with identical DNA binding features. A member of the family of RFX factors is affected in an autosomal recessive disease, MHC class II deficient combined immunodeficiency (CID), caused by a defect in a trcme-acting regulatory factor controlling MHC class II gene expression. In situ hybriciation with sH-labeled RFXl cDNA has allowed us to identify two distinct targets on the short arm of chromosome 19 (19~13.1 and 19p13.2-~13.3). With the use of biotinylated genomic cosmid clones specific for RFXl and RFXB, respectively,‘it was then possible to localize RFXl at 19~13.1 and RFX2 at 19p13.2-~13.3. These two regulatory genes are thus assigned to a region of high gene density and RFXl is close to another DNA-binding factor, LYLl. Q 1992 Academic F’mm, Inc.
The three forms of human MHC class II molecules, HLA-DR, -DQ, and -DP, are encoded by closely linked and homologous cyand fi chain genes, located in the centromeric portion of the MHC, on the short arm of chromosome 6. Class II molecules are involved in the presentation of antigens to T lymphocytes, and the highly specific regulation of expression of class II genes is thus directly relevant to the control of the immune response. A form of hereditary immunodeficiency, HLA class II deficient combined immunodeficiency (CID), is characterized by a lack of expression of HLA class II genes (7). It was shown to be an autosomal recessive disease and to result from a defect in a tram-acting regulatory factor (4,s The expression of HLA class II genes is controlled primarily by c&acting DNA motifs located within the 150 bp upstream of the genes and in particular by two highly conserved sequences, the X and the Y boxes. Several protein factors have been shown to bind to these &-acting sequences and to have very specific contact points on the DNA. Figure 1 is a schematic representation of an HLA class II promoter, with certain of these protein factors [see reviews in Refs. (1,9,12)]. The case of factor RFX is of special interest since a specific defect in the binding of RFX to its target DNA sequence has been observed in patients with HLA class II deficient combined immunodeficiency (14). Following the cloning 1307
of RFX (14), it was possible to show that overexpression of RFX in transfected cells does indeed transactivate an HLA class II promoter (in preparation) and that antisense RNA expressed in transfected cells does inhibit the expression of HLA-DR genes in these cells (16). RFX is therefore a functionally relevant regulator of MHC class II gene expression. Recently, a second gene, encoding a second form of RFX, has been isolated and shown to have identical DNA-binding characteristics (unpublished). The genes corresponding to these two highly related forms of RFX are referred to as RFXl and RFXZ. In situ hybridization was performed according to Mattei et ~2. (9) on chromosome spreads obtained from phytohemagglutinin-stimulated peripheral blood lymphocyte cultures from three normal male donors. The first probe was a 1.6-kb DNA fragment derived from the RFXl cDNA clone (nucleotides 557-1899) (16), labeled by nick translation with 3H to a specific activity of O.&J1.5 X lo6 cpm/pg. After autoradiography, the preparations were stained with Giemsa for counting grains, and R and G bands were then obtained using the fluorochrome-photolysis-Giemsa (FPG) technique (9). Metaphases with 46 chromosomes and no more than 5 grains were selected for analysis. A total of 109 autoradiographic grains were scored in 52 metaphase chromosome spreads. This revealed a clustering of grains (34%) on the short arm of chromosome 19, as shown in Fig. 2A. The remaining grains were scattered more or less evenly over all the chromosomes (Fig. 2A). A small increase in grain number was noted on the long arm of chromosome 9. Three metaphases showed label on both chromosomes CLONED TRANSACTING
FACTORS
NF-YA/NF-YB
W
OCTl ocr2
CRE ‘X-ACTING
FIG. 1. Schematic representation the HLA DRA promoter.
SEQUENCES
of the factors known to bind to CENOMICS
13, 1307-1310 (19%) o&388-7543/92 $5.00
Copyright 0 1992 by Academic Press, Inc. All rights of reproduction in any form reserved.
1308
SHORT
COMMUNICATION
A Number of grains 10 8
q 1 132 133
134
19
FIG. 2. Localization of the RFXl and RFX2 genes on 19p. (A) Histogram of the distribution of grains in 52 metaphases, obtained after in situ hybridization with an 3H-labeled RFX-1 probe. The majority of grains is located on the short arm of the chromosome 19. (9) Distribution of silver grains on 29 selected chromosomes 19. The majority is on 19p13.1 and on ~13.3. (C) Hybridization with biotinylated cosmid probes for RFXl and RFXB. Examples of hybridization patterns observed on chromosome 19 for RFXl (C24) and RFX2 (C8).
19. The RFXl gene is thus localized on the short arm of chromosome 19. The localization of the RFXl gene within the short arm of chromosome 19 was then analyzed with metaphases selected for chromosome length, 12 with G banding and 17 with R banding (6). The 31 grains examined had the distribution shown in Fig. 2B, with signals over 19p13.1 and 19p13.2 and 3. Two cosmid clones containing about 30 kb of genomic DNA, isolated from a human cosmid library (17), were shown to correspond to the genes for RFXl (cosmid C24) and RFX2 (cosmid C8) (Ucla et al., in preparation). In the portion encoding the DNA-binding domain and the dimerization domains, the amino acid sequences of RFXl and RFX2 show more than 90 and 85% homology, respectively, and the two recombinant proteins can bind the X box as homo- or heterodimers (in preparation). These two cosmid probes were labeled with bio-ll-
dUTP (Sigma) by nick translation and were then prepared according to Cherif et al. (3). Competitive in situ hybridization and in situ hybridization were performed according to Cherif et al. (3). For each probe, concentrations of 1 @g/ml, 500 rig/ml, and 250 rig/ml were used in the hybridization mixture. The hybridization signal was revealed by avidin-conjugated fluorescein isothiocyanate (FITC) and amplified with additional layers of biotinylated goat anti-avidin antibody as previously described (13). R bands were obtained according to Cherif et al. (3). The slides were screened with a Zeiss fluorescence microscope equipped with filter No. 487709. With cosmid C24 as probe (RFXl), a spot on both chromatids was present in 16 metaphases on 19p13.1 on both chromosomes 19. With cosmid C8 as probe (RFX2), hybridization signals were localized as double spots on sister chromatids on 19p13.3 on both chromosomes 19 in 39
SHORT
1309
COMMUNICATION
metaphases and on only one chromosome in 3 metaphases (data not shown). These spots were very close to 19p13.2. In the metaphases with elongated chromosomes, the localization was 191313.31. Figure 2C confirms the distinct position of the two genes on p19. From these data, we conclude that RFXl is located on 19p13.1, while RFX2 is located on the same chromosome at position p13.2-~13.3. The two types of probes used in this study have different characteristics. The RFXl cDNA probe (1.6 kb) is known to hybridize to both RFXl and RFXB. This cross-hybridization is due to regions of extensive sequence homology in the coding portion of RFXl and RFX2 (16; Ucla et al., in preparation). The two cosmid clones, on the other hand, contain about 30 kb of genomic DNA and represent probes specific for each of the two genes. Only a very small portion of these sequences is represented by exons from RFXl or RFXS, and these two probes are thus not expected to cross-hybridize significantly under the experimental conditions used. Hybridization with biotin-labeled genomic cosmid clones corresponding to the RFXl and RFX2 genes confirmed the localization of these two RFX genes to 19p13 and they positioned RFXl at 19p13.1 and RFX2 at a more distal position on the same chromosome, 19p13.3 or 19p13.2-p13.3. The discrimination between the position of RFXl and RFX2 was confirmed in several metaphases and several examples are shown in Fig. 2C. Chromosome 19 has been extensively mapped. It has been suggested that it is unusual in having a higher “gene density” than other human chromosomes (10). The position of the RFXl gene indicates that it is close to LYLl, a gene that also encodes a DNA-binding transcription factor (11). Other genes known to map to this chromosomal region include MEL, JUNB, JUND, RAB3A, and EPOR (B. Trask, personal communication). The cloned RFXl and RFX2 genes will therefore contribute to the fine map of the short arm of chromosome 19. In particular, they are now used to position the RFX genes on the cosmid contig maps being developed at the Lawrence Livermore National Laboratory. RFXl has been well characterized structurally and functionally. It behaves as a transactivator of the HLADR promoter in transfection experiments, and expression of antisense RFXl RNA inhibits the expression of HLA-DR (16, and unpublished data). RFXl is therefore a trans-acting regulatory factor of MHC class II gene expression. The RFX2 gene, however, has not yet been studied functionally. The deduced RFX2 protein is almost identical to RFXl over certain functionally relevant portions of the molecule, including the DNA-binding and dimerization domains (in preparation). The recent discovery of yet a third RFX-related cDNA suggests the existence of a novel family of X box-binding factors that probably all exhibit the same DNA-binding properties to the X box of MHC class II promoters. The elucidation of their individual role in the control of MHC class II expression will represent a major chal-
lenge. HLA class II deficient combined immunodeficiency is a rare autosomal recessive disease characterized by an absence of HLA class II expression (7). It was shown to result from a defect in a tram-acting regulatory factor that is unlinked to the MHC and controls MHC class II gene expression (4). The molecular defect in this disease was then identified as an absence of binding of a DNA-binding factor specific for the X box motif of HLA class II promoters (14). Class II deficient CID thus represents the first disease attributed to a defect in a DNAbinding regulatory factor. It is not yet established whether the genetic defect in this disease concerns RFXl, RFXB, or another member of this novel family of related MHC class II X box-binding factors. The recent cloning of RFX2 and of additional members of this family should permit a systematic study of the X box-binding factor, or factors, implicated in this disorder.
ACKNOWLEDGMENTS Work was supported by grants from the Swiss National Science Foundation, the Jeantet Foundation and from the French Ministry of Researchand Technology (Grant MRT 89CO878). We are grateful to Dr. M. G. Mattei and Ms. E. Passage in Marseilles laux and Dr. F. Apiou in Paris for helpful advice tion.
and Dr. B. Dutrilon in situ hybridiza-
REFERENCES 1.
Benoist, patibility alphabet.
2.
Camargo, M., and Cervenka, replication in synchronized and replication model. Am.
3.
Cherif, D., Julier, C., Delattre, O., Derre, J., Lathrop, G. M., and Berger, R. (1990). Simultaneous localization of cosmids and chromosome R-banding by fluorescence microscopy: Application to regional mapping of human chromosome 11. Proc. Natl. Acad. Sci. USA 87: 6639-6643.
4.
de Preval, C., Lisowska-Grospierre, B., Loche, M., Griscelli, C., and Mach, B. (1985). A transacting class II regulatory gene unlinked to the MHC controls expression of HLA class II genes. Nature 318: 291-293.
5.
de P&al, C., Hadam, M. R., and Mach, genes for HLA class II antigens in cell severe combined immunodeficiency. N. 1300. Dutrillaux, B., Couturier, J., Richer, Pequignot, E. (1976). Sequence of DNA Q-bands of human chromosomes using mosoma 58: 51-61.
6.
7.
8. 9.
C., and Mathis, D. (1990). Regulation of major histocomcomplex class-II genes: X, Y and other letters of the Annu. Reu. Zmmunol. 8: 681-715. J. (1980). Pattern of chromosomal lymphocytes. II. Replication map J. Hum. Genet. 34: 757-780.
B. (1988). Regulation of lines from patients with Engl. J. Med. 318: 1295C.-L., and Viegasreplication in 277 R- and a BrdU treatment. Chro-
Griscelli, C., Lisowska-Grospierre, B., and Mach, B. (1989). Combined immunodeficiency with defective expression in MHC class II genes. Zmmunodeficiency Reu. 1: 135-153. Kara, C. J., and Glimcher, L. H. (1991). Regulation of MHC class II gene transcription. Current Op. Zmmunol. 3: 16-21. Mattei, M. G., Philip, N., Passage, E., Moisan, J. P., Mandel, J. L., and Mattei, J. F. (1985). DNA probe localization at 18~113 band by in situ hybridization and identification of a small supernumerary chromosome. Hum. Genet. 69: 268-271.
1310
SHORT
10.
McKusick, V. A. (1991). genes. FASEB J. 5: 12-20.
11.
Mellentin, J. D., Smith, S. D., and Cleary, M. L. (1989). 1~1-1, a novel gene altered by chromosomal translocation in T cell leukemia, codes for a protein with a helix-loop-helix DNA binding motivf. Cell 58: 77-83.
12.
Current
Peterlin, B. M., Anderson, G., (1990). Transcriptional regulation munol. Res. 9: 1644177.
trends
Lotscher, of HLA
in mapping
COMMUNICATION human
E., and Tsang, class II genes.
J. W. (1986). fluorescence
S., Zm-
13.
Pinkel, D., Straube, T., and Gray, analysis using quantitative high Proc. Natl. Acad. Sci. 83: 2934-2938.
14.
Reith, W., Satola, S., Herrero Sanchez, C., Amaldi, I., LisowskaGrospierre, B., Griscelli, C., Hadam, M. R., and Mach, B. (1988).
Congenital immunodeficiency with a regulatory class II gene expression lacks a specific HLA-DR ing protein, RF-X. Cell 53: 897-906.
defect in MHC promoter bind-
15.
Reith, W., Barras, Sanchez, C., and promoter binding II gene regulation.
16.
Reith, W., Herrero-Sanchez, C., Kobr, M., Silacci, P., Berte, Ch., Barras, E., Fey, S., and Mach, B. (1990). MHC class II regulatory factor RFX has a novel DNA-binding domain. Genes Deu. 4: 15281540.
17.
Rollini, P., Mach, HlA-DR b-chain Proc. Natl. Acad.
Cytogenetics hybridization.
E., Satola, S., Kobr, M., Reinharz, D., Herrero Mach, B. (1989). Cloning of the MHC class II protein affected in a hereditary defect in class hoc. Natl. Acad. Sci. USA 86: 4200-4204.
B., and Gorski, J. (1985). Linkage map of three genes: Evidence for a recent duplication event. Sci. USA 82: 7197-7201.