- Email: [email protected]
Tetratrico peptide repeats are present in the kinesin light chain
LETTERS 17 Ramage, L. etal. (1993) EMBOJ. 12,
4115-4123 18 Goping, I. S., Millar, D. G. and Shore, G. C. (1995) FEBS Lett. 373, 45-50 19 Seki, N. et al. (1995) FEBS Lett., 375, 307-310 20 S(~llner,1. et al. (1992) Nature 355, 84-87 21 Alconada, A. et al. (1995) Mol. Cell. Biol. 15, 6196-6205 22 Kassenbrock, C. K., Cao, W. and Douglas, M. G. (1993) EMBO J. 12, 3023-3034 23 Maarse, A. C., Blom, J., Gdvell, L. A. and Meijer, M. (1992) EMBO J. 11, 3619-3628 24 Scherer, P. E. et al. (1992) Prec. Natl Acad. Sci. USA 89, 11930-11934 25 Blom, J. et al. (1993) MoI. Cell. Biol. 13, 7364-7371 26 Horst, M. et al. (1993) EMBO J. 12, 3035-3041 27 Emtage, J. L. T. and Jensen, R. E. (1993) J. Cell Biol. 122, 1003-1012 28 Dekker, P. J. E et al. (1993) FEBS Lett. 330, 66-70 29 Maarse, A. C. et al. (1994) FEBS Lett. 349, 215-221 30 Ryan, K. R., Menold, M. M., Garett, S. and Jensen, R. E. (1994) Mol. Biol. Cell 5, 529-538
Tetratrico peptide repeats are present in the kinesin light chain The tetratrico peptide repeat (TPR) motif is a modular 34 amino acid sequence that mediates intermolecular or intramolecular protein-protein interactions in a large array of structurally and functionally diverse proteins 1 (see Fig. l a on opposite page). It is predicted to form two short amphipathic cr helices, a 'knob' domain and a 'hole' domain, which are essential for TPR function 2~. We report here that the Drosophila kinesin light chain (KLC) is a TPR protein and propose that the TPR motifs of KLC might mediate the interaction of kinesin with intracellular cargoes. To complement our ongoing analysis of Drosophila KLC function, we performed a BLASTP search 5 of the NCBI peptide sequence database, using amino acids 179-468 of Drosophila KLC6 as the query sequence. This region of KLC contains six imperfect repeats that are highly conserved in KLCs from both v e r t e b r a t e s and invertebrates 6-1~ (Fig. la). The results of this search and of a second BLASTP query, using the region of CELK04G7.3 most similar to KLC, raised the possibility that KLC contains TPR motifs. Figure l a shows that at least five out of eight residues of the TPR consensus z,3 are conserved in each KLC repeat, and that the identity of individual
52
TIBS 2 1 - F E B R U A R Y 1 9 9 6
NIKOLAUS PFANNER
MICHIEL MEIJER
Institut ffir Biochemie und Molekularbiologie, Universit~t Freiburg, Hermann-Herder-Straf~e7, D-79104 Freiburg, Germany.
Institute for Molecular Cell Biology, BioCentrum Amsterdam, 1098 SM Amsterdam, The Netherlands.
MICHAEL G. DOUGLAS
WALTER NEUPERT
Sigma-AldrichCorporation,St Louis, MO 63103, USA.
Institut ffir Physiologische Chemie der Universit~t Mfinchen, D~0336 Mfinchen, Germany.
TOSHIYA ENDO
GOTTFRIED SCHATZ
Department of Chemistry, Nagoya University, Nagoya 464-01, Japan.
NICHOLAS J. HOOGENRAAD School of Biochemistry, La Trobe University, Bundoora, Victoria 3083, Australia.
ROBERT E. JENSEN
Biozentrum, University of Basel, CH-4056 Basel, Switzerland.
UDO K. SCHMITZ Institut ffir Angewandte Genetik, Universit~t Hannover, D-30419 Hannover, Germany.
GORDON C. SHORE
Department of Cell Biology and Anatomy, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
KLC repeats with the SNAP TPR consensus ranges from 44% to 59%, which is comparable to the degree of identity observed for other TPR proteins ]2. In addition, the predicted s e c o n d a r y structure of the KLC repeats is similar to the TPR motif (Fig. 11)). These results strongly suggest that the KLC repeat is homologous to the TPR motif. Several functions have been proposed for KLC, such as mediating the tethering of intracellular cargoes to the kinesin motor domain, regulating the motor activity of the kinesin heavy chain, or regulating the interaction of the carboxyl terminus of the kinesin heavy chain with cargoes (see Ref. 13 for review). The presence of TPR motifs in KLC suggests that the KLC repeats have an active role in the protein-protein interactions necessary for kinesin-based intracellular transport, either in the binding of intracellular cargoes or the regulation of kinesin motor activity. Tzamarias and Struhl have shown that the region of TUP1 that interacts with TPR motifs 1-3 of CYC8 (SSN6) forms a predicted coiledcoil 14. An attractive (and testable) hypothesis is that the KLC repeats mediate cargo binding by interacting with the p r o p o s e d coiled-coil of kinectin, a cargo-bound receptor of kinesin, in a manner similar to the interaction between CYC8 and TUP1 (Refs 15-17).
References 1 Lamb, J. R., Tugendreich, S. and Heiter, P. (1995) Trends Biochem. Sci. 20, 257-259 2 Sikorski, R. S., Boguski, M. S., Goebl, M. and Heiter, P. (1990) Cell 60, 307-317
Department of Biochemistry, McGill University, Montreal, Quebec, Canada H3G 1Y6.
3 Hirano, T., Kinoshita, N., Morikawa, K. and Yanagida, M. (1990) Cell 60, 319-328 4 Lamb, J. R., Michaud, W. A., Sikorski, R. S. and Heiter, P. A. (1994) EMBO J. 13, 4321-4328 5 Altshul, S. F. et al. (1990) J. Mol. Biol. 215, 403-410 6 Gauger, A. K. and Goldstein, L. S. B. (1993) J. Biol. Chem. 268, 13657-13666 7 Cyr, J. L. et al. (1991) Proc. Natl Acad. Sci. USA 88, 10114-10118 8 Wedaman, K. P., Knight, A. E., Kendrick-Jones, J. and Scholey, J. M. (1993) J. MoI. Biol. 231, 155-158 9 Beushausen, S., Ktadakis, A. and Jaffe, H. (1993) DNA Cell Biol. 10, 901-909 10 Cabeza-Arvelaiz, Y. et al. (1993) DNA Cell Biol. 12,881-892 i l Fan, J. and Amos, L. A. (1994) J. Mol. Biol. 240, 507-512 12 Ordway, R. W., Pallanck, L. and Ganetzky, B. (1994) Trends Biochem. Sci. 19,530-531 13 Coy, D. L. and Howard, 3. (1994) Curr. Opin. Cell Biol. 4, 662-667 14 Tzamarias, D. and Struhl, K. (1995) Genes Dev. 9, 821-831 15 Kumar, J., Yu, H. and Sheetz, M. P. (1995) Science 267, 1834-1837 16 Fetterer, A. et al. (1995) Mol. Biol. Cell 6, 161-170 17 Yu, H. et al. (1995) Mol. Biol. Cell 6, 171-183 18 Wilson, R. et al. (1994) Nature 368, 32-38 19 Honor(~, B. et al. (1992) J. Biol. Chem. 267, 8485-8491 20 Devereux, J., Haeberli, P. and Smithies, O. (1984) Nucleic Acids Res. 12, 387-395 21 Goebl, M. and Yanagida, M. (1991) Trends Biochem. Sci. 16, 173-177
JOSEPH G. GINDHART, JR AND LAWRENCE S. B. GOLDSTEIN Howard Hughes Medical Institute, Division of Cellular and Molecular Medicine, Department of Pharmacology, UCSD School of Medicine, 9500 Gilman Drive 0683, La Jolla, CA 92093-0683, USA.
9 1996, Elsevier Science Ltd
LETTERS
TIBS 2 1 - FEBRUARY 1996
Figure 1 Spacer TPR motif (a) Alignment of Drosophila kinesin I I light chain (KLC) repeats with Repeat 1 177 the tetratrico peptide repeats Repeat2 219 (TPR) and SNAP TPR consensus ~ "~ i o r 9 T l i ~vi~ ~ l l ~ i ~ ~.i~ .11 ~ ~ 1 ~ ~ i ~ Repeat3 261 sequences, comparison of the ~. ~ . l ~ l ~ T i w i ~i~i~i ~.~i~g~.~i ~ secondary structure of the KLC Repeat4 303 v ~, ~~. i ~ r ~ O l . i ~,~.i o . i ~ i ~ T ~ i ~~ i ~ ~ i ~ repeat consensus and the TPR Repeat 5 345 consensus, and a represent~ ~i"i ~i~i ~ Lb'4R ~ ~ R' ~~ Mi~~Ei ~Ar-qE T ~ i T ~ D ~ C~~ R ~ Si K ~ E~ AA V D S ~T~T T T~K~A Repeat6 428 ation of KLC secondary structure. A BLASTP5 search of a W LG Y A F A P TPR consensus nonredundant NCBI peptide sequence database (10 July 1995) A A D * Y E x A A D * Y E x A A D Y E x A A D * Y E x A A D * Y E x SNAPconsensus was performed using Drosophila GECFK GECFK GEFK GECFK GECFK KLC amino acids 179-468 as the query sequence6. Three highly IN L IN L INL INL IN L *=V,t, L, M,A significant scores (p < 0.001) x= K, R,Q, N, D, E were obtained: SC8270.16 (K. Devlin and C. M. Churcher, unpublished), CELKO4G7.3 (Ref. 18), and IEF SSP 3521 (Ref. 19). Subsequent BLASTPsearch query Y sequences were SC8270.16 amino acids 995-1088 and CELKO4G7.3 amino acids 406-537. SC8270.16 showed no significant similarity to any ~L protein other than itself and KLC. However, amino acids 406-537 of CELKO4G7.3 were Y very similar to KLCs, including W Drosophila KLC (p = 1.0e-14), and to TPR proteins, including IEF SSP 3521 (P = 3.2e-7). 96 Initial alignments of the KLC repeats to the SNAP TPR consensus were performed manu(c) ally, using the similarity of IEF SSP 3521 TPR6 and KLC repeat 2 (P = 0.00067) as a guide. coiled-coil repeat 1 repeat2 repeat3 repeat4 repeat5 repeat6 Manual alignments of the KLC repeats with the TPR consensus sequence were confirmed by GAP and BESTFIT2~comparisons of KLC to the TPR consensus sequence and to TPR proteins such as IEF SSP 3521, SSN6 and MOM70 (data not shown). No kinesin superfamily members were identified by our BLASTP searches, suggesting that TPR motifs are not present in the tail domain of other kinesin-like proteins. Accession numbers were as follows: KLC, GenBank Ll1013; SC8270.16, GenBank Z48613; CELKO4G7.3, GenBank U21320; IEF SSP 3521, SWlSS-PROT P31948; SSN6, SWlSS-PROT P14922; MOM70, SWlSS-PROT P23231. (a) The alignment of KLC repeats 1-6 (Ref. 6) to each other and to the general TPR consensus 2 and the SNAP TPR consensus 12 are shown. Green boxes denote residues that are identical in at least five out of six KLC repeats and red boxes represent the position of the TPR consensus residues. Note the presence of an eight amino acid 'spacer' between tandemly arranged TPR repeats that might substitute for the proline 'hinge' normally found at position 33 of the TPR motif. (b) The secondary structure of KLC repeats is similar'to TPR motifs. Edmunson wheel diagrams of a consensus KLC repeat were generated using the HELICALWHEELprogram2~and compared with a previously described wheel diagram of the TPR consensus sequence2. The distribution of charged residues on the opposite side of the hydrophobic faces of domains A and B are also conserved (data not shown). (r Representation of KLC secondary structure. Drosophila KLC is 508 amino acids in length. The amino-terminal coiled-coil of KLC interacts with the tail of the kinesin heavy chain 6. KLC repeats 1-5 (large ovals) are tandemly arranged, and are separated from repeat 6 by 41 amino acids. The arrangement of TPR motifs in KLC is similar to that observed in other TPR proteins (see Refs 1, 21).
,..STOP P R ~ , . . The TIBS newslpoup is now on the WWW! You can now access the TiBS newsgroup and all other BIOSCI newsgroups [TiBS (1993) 18, 310-311] by connecting to the URL h t l ~ : / / w w w . ~ . n e t then clicking on the 'Access the BIOSCI/bionet Newsgroups' hyperlink. As long as your Web browser is correctly configured to send Email, you can not only read these messages, but also post public messages to the newsgroup, or send private replies to a respondent. 53
4115-4123 18 Goping, I. S., Millar, D. G. and Shore, G. C. (1995) FEBS Lett. 373, 45-50 19 Seki, N. et al. (1995) FEBS Lett., 375, 307-310 20 S(~llner,1. et al. (1992) Nature 355, 84-87 21 Alconada, A. et al. (1995) Mol. Cell. Biol. 15, 6196-6205 22 Kassenbrock, C. K., Cao, W. and Douglas, M. G. (1993) EMBO J. 12, 3023-3034 23 Maarse, A. C., Blom, J., Gdvell, L. A. and Meijer, M. (1992) EMBO J. 11, 3619-3628 24 Scherer, P. E. et al. (1992) Prec. Natl Acad. Sci. USA 89, 11930-11934 25 Blom, J. et al. (1993) MoI. Cell. Biol. 13, 7364-7371 26 Horst, M. et al. (1993) EMBO J. 12, 3035-3041 27 Emtage, J. L. T. and Jensen, R. E. (1993) J. Cell Biol. 122, 1003-1012 28 Dekker, P. J. E et al. (1993) FEBS Lett. 330, 66-70 29 Maarse, A. C. et al. (1994) FEBS Lett. 349, 215-221 30 Ryan, K. R., Menold, M. M., Garett, S. and Jensen, R. E. (1994) Mol. Biol. Cell 5, 529-538
Tetratrico peptide repeats are present in the kinesin light chain The tetratrico peptide repeat (TPR) motif is a modular 34 amino acid sequence that mediates intermolecular or intramolecular protein-protein interactions in a large array of structurally and functionally diverse proteins 1 (see Fig. l a on opposite page). It is predicted to form two short amphipathic cr helices, a 'knob' domain and a 'hole' domain, which are essential for TPR function 2~. We report here that the Drosophila kinesin light chain (KLC) is a TPR protein and propose that the TPR motifs of KLC might mediate the interaction of kinesin with intracellular cargoes. To complement our ongoing analysis of Drosophila KLC function, we performed a BLASTP search 5 of the NCBI peptide sequence database, using amino acids 179-468 of Drosophila KLC6 as the query sequence. This region of KLC contains six imperfect repeats that are highly conserved in KLCs from both v e r t e b r a t e s and invertebrates 6-1~ (Fig. la). The results of this search and of a second BLASTP query, using the region of CELK04G7.3 most similar to KLC, raised the possibility that KLC contains TPR motifs. Figure l a shows that at least five out of eight residues of the TPR consensus z,3 are conserved in each KLC repeat, and that the identity of individual
52
TIBS 2 1 - F E B R U A R Y 1 9 9 6
NIKOLAUS PFANNER
MICHIEL MEIJER
Institut ffir Biochemie und Molekularbiologie, Universit~t Freiburg, Hermann-Herder-Straf~e7, D-79104 Freiburg, Germany.
Institute for Molecular Cell Biology, BioCentrum Amsterdam, 1098 SM Amsterdam, The Netherlands.
MICHAEL G. DOUGLAS
WALTER NEUPERT
Sigma-AldrichCorporation,St Louis, MO 63103, USA.
Institut ffir Physiologische Chemie der Universit~t Mfinchen, D~0336 Mfinchen, Germany.
TOSHIYA ENDO
GOTTFRIED SCHATZ
Department of Chemistry, Nagoya University, Nagoya 464-01, Japan.
NICHOLAS J. HOOGENRAAD School of Biochemistry, La Trobe University, Bundoora, Victoria 3083, Australia.
ROBERT E. JENSEN
Biozentrum, University of Basel, CH-4056 Basel, Switzerland.
UDO K. SCHMITZ Institut ffir Angewandte Genetik, Universit~t Hannover, D-30419 Hannover, Germany.
GORDON C. SHORE
Department of Cell Biology and Anatomy, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
KLC repeats with the SNAP TPR consensus ranges from 44% to 59%, which is comparable to the degree of identity observed for other TPR proteins ]2. In addition, the predicted s e c o n d a r y structure of the KLC repeats is similar to the TPR motif (Fig. 11)). These results strongly suggest that the KLC repeat is homologous to the TPR motif. Several functions have been proposed for KLC, such as mediating the tethering of intracellular cargoes to the kinesin motor domain, regulating the motor activity of the kinesin heavy chain, or regulating the interaction of the carboxyl terminus of the kinesin heavy chain with cargoes (see Ref. 13 for review). The presence of TPR motifs in KLC suggests that the KLC repeats have an active role in the protein-protein interactions necessary for kinesin-based intracellular transport, either in the binding of intracellular cargoes or the regulation of kinesin motor activity. Tzamarias and Struhl have shown that the region of TUP1 that interacts with TPR motifs 1-3 of CYC8 (SSN6) forms a predicted coiledcoil 14. An attractive (and testable) hypothesis is that the KLC repeats mediate cargo binding by interacting with the p r o p o s e d coiled-coil of kinectin, a cargo-bound receptor of kinesin, in a manner similar to the interaction between CYC8 and TUP1 (Refs 15-17).
References 1 Lamb, J. R., Tugendreich, S. and Heiter, P. (1995) Trends Biochem. Sci. 20, 257-259 2 Sikorski, R. S., Boguski, M. S., Goebl, M. and Heiter, P. (1990) Cell 60, 307-317
Department of Biochemistry, McGill University, Montreal, Quebec, Canada H3G 1Y6.
3 Hirano, T., Kinoshita, N., Morikawa, K. and Yanagida, M. (1990) Cell 60, 319-328 4 Lamb, J. R., Michaud, W. A., Sikorski, R. S. and Heiter, P. A. (1994) EMBO J. 13, 4321-4328 5 Altshul, S. F. et al. (1990) J. Mol. Biol. 215, 403-410 6 Gauger, A. K. and Goldstein, L. S. B. (1993) J. Biol. Chem. 268, 13657-13666 7 Cyr, J. L. et al. (1991) Proc. Natl Acad. Sci. USA 88, 10114-10118 8 Wedaman, K. P., Knight, A. E., Kendrick-Jones, J. and Scholey, J. M. (1993) J. MoI. Biol. 231, 155-158 9 Beushausen, S., Ktadakis, A. and Jaffe, H. (1993) DNA Cell Biol. 10, 901-909 10 Cabeza-Arvelaiz, Y. et al. (1993) DNA Cell Biol. 12,881-892 i l Fan, J. and Amos, L. A. (1994) J. Mol. Biol. 240, 507-512 12 Ordway, R. W., Pallanck, L. and Ganetzky, B. (1994) Trends Biochem. Sci. 19,530-531 13 Coy, D. L. and Howard, 3. (1994) Curr. Opin. Cell Biol. 4, 662-667 14 Tzamarias, D. and Struhl, K. (1995) Genes Dev. 9, 821-831 15 Kumar, J., Yu, H. and Sheetz, M. P. (1995) Science 267, 1834-1837 16 Fetterer, A. et al. (1995) Mol. Biol. Cell 6, 161-170 17 Yu, H. et al. (1995) Mol. Biol. Cell 6, 171-183 18 Wilson, R. et al. (1994) Nature 368, 32-38 19 Honor(~, B. et al. (1992) J. Biol. Chem. 267, 8485-8491 20 Devereux, J., Haeberli, P. and Smithies, O. (1984) Nucleic Acids Res. 12, 387-395 21 Goebl, M. and Yanagida, M. (1991) Trends Biochem. Sci. 16, 173-177
JOSEPH G. GINDHART, JR AND LAWRENCE S. B. GOLDSTEIN Howard Hughes Medical Institute, Division of Cellular and Molecular Medicine, Department of Pharmacology, UCSD School of Medicine, 9500 Gilman Drive 0683, La Jolla, CA 92093-0683, USA.
9 1996, Elsevier Science Ltd
LETTERS
TIBS 2 1 - FEBRUARY 1996
Figure 1 Spacer TPR motif (a) Alignment of Drosophila kinesin I I light chain (KLC) repeats with Repeat 1 177 the tetratrico peptide repeats Repeat2 219 (TPR) and SNAP TPR consensus ~ "~ i o r 9 T l i ~vi~ ~ l l ~ i ~ ~.i~ .11 ~ ~ 1 ~ ~ i ~ Repeat3 261 sequences, comparison of the ~. ~ . l ~ l ~ T i w i ~i~i~i ~.~i~g~.~i ~ secondary structure of the KLC Repeat4 303 v ~, ~~. i ~ r ~ O l . i ~,~.i o . i ~ i ~ T ~ i ~~ i ~ ~ i ~ repeat consensus and the TPR Repeat 5 345 consensus, and a represent~ ~i"i ~i~i ~ Lb'4R ~ ~ R' ~~ Mi~~Ei ~Ar-qE T ~ i T ~ D ~ C~~ R ~ Si K ~ E~ AA V D S ~T~T T T~K~A Repeat6 428 ation of KLC secondary structure. A BLASTP5 search of a W LG Y A F A P TPR consensus nonredundant NCBI peptide sequence database (10 July 1995) A A D * Y E x A A D * Y E x A A D Y E x A A D * Y E x A A D * Y E x SNAPconsensus was performed using Drosophila GECFK GECFK GEFK GECFK GECFK KLC amino acids 179-468 as the query sequence6. Three highly IN L IN L INL INL IN L *=V,t, L, M,A significant scores (p < 0.001) x= K, R,Q, N, D, E were obtained: SC8270.16 (K. Devlin and C. M. Churcher, unpublished), CELKO4G7.3 (Ref. 18), and IEF SSP 3521 (Ref. 19). Subsequent BLASTPsearch query Y sequences were SC8270.16 amino acids 995-1088 and CELKO4G7.3 amino acids 406-537. SC8270.16 showed no significant similarity to any ~L protein other than itself and KLC. However, amino acids 406-537 of CELKO4G7.3 were Y very similar to KLCs, including W Drosophila KLC (p = 1.0e-14), and to TPR proteins, including IEF SSP 3521 (P = 3.2e-7). 96 Initial alignments of the KLC repeats to the SNAP TPR consensus were performed manu(c) ally, using the similarity of IEF SSP 3521 TPR6 and KLC repeat 2 (P = 0.00067) as a guide. coiled-coil repeat 1 repeat2 repeat3 repeat4 repeat5 repeat6 Manual alignments of the KLC repeats with the TPR consensus sequence were confirmed by GAP and BESTFIT2~comparisons of KLC to the TPR consensus sequence and to TPR proteins such as IEF SSP 3521, SSN6 and MOM70 (data not shown). No kinesin superfamily members were identified by our BLASTP searches, suggesting that TPR motifs are not present in the tail domain of other kinesin-like proteins. Accession numbers were as follows: KLC, GenBank Ll1013; SC8270.16, GenBank Z48613; CELKO4G7.3, GenBank U21320; IEF SSP 3521, SWlSS-PROT P31948; SSN6, SWlSS-PROT P14922; MOM70, SWlSS-PROT P23231. (a) The alignment of KLC repeats 1-6 (Ref. 6) to each other and to the general TPR consensus 2 and the SNAP TPR consensus 12 are shown. Green boxes denote residues that are identical in at least five out of six KLC repeats and red boxes represent the position of the TPR consensus residues. Note the presence of an eight amino acid 'spacer' between tandemly arranged TPR repeats that might substitute for the proline 'hinge' normally found at position 33 of the TPR motif. (b) The secondary structure of KLC repeats is similar'to TPR motifs. Edmunson wheel diagrams of a consensus KLC repeat were generated using the HELICALWHEELprogram2~and compared with a previously described wheel diagram of the TPR consensus sequence2. The distribution of charged residues on the opposite side of the hydrophobic faces of domains A and B are also conserved (data not shown). (r Representation of KLC secondary structure. Drosophila KLC is 508 amino acids in length. The amino-terminal coiled-coil of KLC interacts with the tail of the kinesin heavy chain 6. KLC repeats 1-5 (large ovals) are tandemly arranged, and are separated from repeat 6 by 41 amino acids. The arrangement of TPR motifs in KLC is similar to that observed in other TPR proteins (see Refs 1, 21).
,..STOP P R ~ , . . The TIBS newslpoup is now on the WWW! You can now access the TiBS newsgroup and all other BIOSCI newsgroups [TiBS (1993) 18, 310-311] by connecting to the URL h t l ~ : / / w w w . ~ . n e t then clicking on the 'Access the BIOSCI/bionet Newsgroups' hyperlink. As long as your Web browser is correctly configured to send Email, you can not only read these messages, but also post public messages to the newsgroup, or send private replies to a respondent. 53