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Trichoderma reesei cellulases, biochemistry, genetics, physiology and applications
900 Moreo~,er. these documented chapters supported by a large and exhaustive list of references allow the various classes of 5-HT receptors (5-HT~. 5-HT,, 5-HT3) and their subtypes (5-HT~A. 5-HTm. 5-HT,c) to be clearly distinguished. Among these chapters, those devoted to the pharmacology and biochemistry of 5-HT~ and 5-HT_, receptors are particularly well presented and that describing autoradiographic studies is very informative. The chap~,ers related to the biochemical mechanisms of receptor action (adenylate cyclase and phosphoinositide hydrolysis) show the complexit.y of ihe studies in this domain and demonstrate clearly that a number of important aspects of the molecular and cellular mechanisms of action related to these receptors are still unknown. The chapter on the 5-HT receptors coupled to adenylate cyclase is particularly clear and exhaustive, and examines some aspects which are usually regarded as being unsolved questions. A very interesting part of the book is that devoted to the relations between the receptors and their cellular function and that exerted at a more integrated level, particularly in behavioral models since serotonin exerts important behavioral controls (feeding, temperature regulation, aggressivity, sexual behavior etc). The essential role of serotonin in vascular smooth muscle leading to the profound and various effects of the amine at the periphery is concisely reviewed and underlines particularly the importance of 5-HT: receptors. Finally, the last section of the book examines the regulation of serotonin receptors in the central nervous system. Attention is focused especially on the effects of agonists and antagonists which alter the number of specific 5-HT receptors; the complexity of the results is clarified by careful analysis. The interactions of antidepressant drugs with serotonergic responsiveness are presented briefly and would have merited more extensive development. The main problem with the book does not concern its intrinsic value since it raises the main questions related to the 5-HT receptors and provides much information in answer to them. However, now in 1990, this book suffers from the fact that it was published in 1988. In the field of 5-HT receptors, the progress in research is so rapid that some important results obtained in recent years could not be reported ie cloning of the receptors (5-HTtA, 5-HT~cN 5-HT_~) structure of the receptor, the probable existence of 5-HT,~, thp ~ ' r . . ,~,~ • . . . . .rr~,~sducti,~a.. . . . . . . . . . . . . . . .~y~t,~,~ ~f ~-,,,3 . . . n,,eu,,,,,,,,.~ of 5-HTIA in anxiety. Therefore, the reader does not have a complete view of the state-of-the-art existing at the present time. In conclusion, this book is very informative, contains most of the experimental facts published up to 1988 and is clearly presented. The reader, a scientist from an academic or industrial laboratory, a student in the field of neurobiology or pharmacology, or more generally everyone involved in the study of the serotonergic system will find a precious source of information in this book. It contains basic knowledge in the 5-HT receptor field so that the reader is then prepared to consult the most recent scientific reports in a fascinating area which is moving ahead at a rapid rate.
Trichoderma reesei Cellulases, Biochemistry, Genetics, Physiology and Applications, edited by CP Kubicek, DE Eveleigh,
H Esterbauer, W Steiner, EM Kubicek-Pranz. The Royal Society of Chemistry, 1990, 250 p, £ 42.50, US$ 82.00 Cellulose is the most abundant carbohydrate produced by plants. As such, the degradation of cellulose is therefore a major component of the carbon cycle. Enzymatic hydrolysis of cellulosic
substrates is far from straightforward, and requires the synergistic interaction of enzymes of various specificity. The study of cellulolytic systems therefore represents an important aspect of basic microbiology and biochemistry. At the peak of the oil crisis in the late 70"s, the biological conversion of cellulosic biomass into fuel and chemicals appeared to be a means of alleviating the energy crisis. Decreasing oil prices and a more realistic assessment of the technical difficulties involved have since made that goal a more remote possibility, even if more limited applications of cellulases are still being considered (eg silage treatment, fruit juice recovery, addition to laundry detergents). Nevertheless, cellulase research is making rapid progress, as shown by the number of interesting meetings held on the subject. This book contains the Proceedings of a meeting held in September 1989 in Vienna on Trichoderma reesei cellulases. That cellulose is indeed a valuable resource should be obvious from the fact that manuscripts originally typed on A-I camera-ready forms were printed half-size. However, any reader interested in cellulases, and endowed with sufficient visual acuity, will be rewarded for his efforts. T reesei has been the most extensively studied celh:iolytic organism since World War II. Not surprisingly, T reesei cellulase has become a reference system, even if it may turn out not to be representative of all cellulales (eg cellulases from anaerobic bacteria). This book comes at a time when the introduction of gene technology to the field is past the first excitement of cloning for its own sake, and biologically relevant questions can be approached with regard to structure-function relationships and regulation. As indicated in the title, the book covers various aspects of Trichoderma cellulase research. The part dealing with the regulation of cellulase synthesis (the paper by El Gogary et al: 'Trichoderma reesei cellulase - from mutants to induction' would belong to that section), is excellent. Kubicek et al give a clear overview of the evidence that cellulase induction most likely involves low molecular weight inducers which are generated from cellulose by constitutive levels of cellulolytic enzymes. The exact mechanism by which the inducers are produced and their chemical nature is not yet clear, however. Likewise, structural and molecular biology aspects are covered by very good presentations. The paper by Henrissat and Mornon on structural homologies between cellulases of various origins should become an obligate reference for anyone embarking on the comparison of cellulase sequences. The article by Teeri et a! shows that the stage is now set for the rational genetic engineering of T reesei cellulases. The structure of the catalytic core of cellobiohydrolase II has been elucidated by X-ray crystallography, and the structure of the cellulose-binding domain has been determined by NMR spectroscopy. Furthermore, a procedure has been developed for the transformation of T reesei, allowing targetted genetic manipulation of the organism. Papers dealing with production and applications are inevitably more descriptive and empirical, and will appear more arduous to the reader who is not directly involved in these aspects, although there is a good discussion of Trichoderma harzianum xylanases by Senior and Saddler. An important point, which is discussed by Teeri et al, is the fact that T reesei, like other filamentous fungi, has a tremendous capacity for secreting proteins. It would thus be a very promising host for expressing rDNA-encoded proteins. Efforts toward this goal have led to the construction of T reesei expression vectors based on fusion with the cbhl, however, and more research will be needed to exploit the full potential of T reesei as a cloning host. The weakest part of the book is the section dealing with the enzymology of T reesei cellulases. After 40 years of research, several aspects are still in a state of confusing controversy. The book contains no view of enzymology problems to match the excellent article of Kubicek et al on regulatory aspects.
901 On the whole, this book gives a concise and up-to-date presentation of the status of research on T reesei cellulases, and should be a valuable purchase for anyone interested in cellulose bioconversion, particularly the basic aspects. P Brguin
The Bacterial Chromosome, edited by K Drlica, M Riley. American Society for Microbiology, 1989, xvi + 469 pp, US$ 63.000 members; US$ 87.00 - non-members
ASM Publications are generally reference books, 'bibles' for scientists in the field they cover. Two recent publications MobileDNA edited by D Berg and M Howe, and The Bacterial Chromosome edited by K Drlica and M Riley deserve special attention. In fact, these books will be useful to scientists not only working in the field of bacterial genetics, but also in all fields involving molecular enetics. This is obvious for DNA mobile elements, since they were discovered by B McClintock in maize, but it is also true for the bacterial chromosome, the structure of which might suggest new concepts in several areas, encompassing structures and dynamics of gene expression. Mobile DNA is present in most, if not all, life forms and although several types of structures can be described (bacteriophages, retroviruses, transposons, insertion sequences, retroposons, retrotransposons) these DNA genes have much in common. Among the 43 papers that constitute the book, one can distinguish between structural, basic, or applied features of mobile DNA. Processes of transposition and insertion are well described, and plenty of references permit identification of important papers in the field. Specific examples are detailed both at the physiological and molecular levels (lambda, Mu, Tn3, Tn5, Tn7, Tnl0). In a series of transition chapters, more exotic organisms such as streptomycetes or holobacteria are reviewed from the point of view of mobile DNA. Agrobacteria permit a shift to be made from procaryotes to eucaryotes, where we begin to discover transposable elements and their effects in nucleated cells. Hybrid dysgenesis in Drosophila permits us to enter in more detail the field of phylogenesis. Retroposons, retrotransposons and repeated DNA are discussed at length and hundreds of references are given, thus permitting the relatively uniformed reader easily to become familiar with the field. The last chapters of this volume are devoted to genome unstabilities resulting from transposition, illegatimate recombination, rearrangements, inversions etc in a wide variety of organisms (fungi, bacteria, trypanosomes, mammalian cells). It is impossible to give a fair account of the immense wealth of data presented in this book. Clearly, all scientists who one day or another may have to consider DNA as a research object of choice should have mobile DNA readily available on their desks. The Bacterial Chromosome, edited by K Drlica and M Riley, is another ASM publication that also deserves much success. Like the preceeding book, but even more easily (because it is of a much smaller format), it could well be stolen from those who are fortunate enough to have it at hand. The book comprises 6 main parts dealing with primary, secondary and tertiary structures of DNA, as well as chromosome replication and segregation or major rearrangements; the last 2 parts are devoted to side issues: the global responses to stress and cryptic genetic information. Fifty years of research on bacteria have produced a fairly comprehensive picture of the bacterial chromosome, and it is now time to give a thorough description of its structure and the initiation and
termination of its replication. The book provides most of the recent literature dealing with the subject, and scientists will find many new insights from the consideration of the whole chromosome rather considered: sporulation ends up with a compact chromosome, thus its study is understandable in the present context, but heatshock seems more indirect... More indirect information comes from the study of the E coli chromosome map by Kohara. This author describes only 450 kbp of DNA as already sequenced, ignoring a very large amount of DNA present in international libraries: this indicates that the Japanese program of E coli chromosome sequencing might be much less advanced that usually assumed. Alternatively, the opposite might be the case and a large amount of DNA could be sequenced! In any case, the book is extremely valuable and will be interesting for all bacteriologists. AL Lecocq
Oxygen Radicals: Systemic Events and Disease Processes. Edited by DK Das, WB Essman, Karger, 1990, xii +196 p, SFr 174 ($116). This book gives an interesting general review of the role of oxygen radicals in the various pathophysiological states in which they are involved. Its 196 pages comprise 7 chapters written by various authors, most, if not all of whom are recognized experts in their fields. Each chapters is itself a general review, including a historical summary and a well-documented analysis of the main fundamental and clinical studies which led to the description of the production and mechanism of action of oxygen radicals towards their targets. The following topics are treated successively. The effect of oxygen radicals on erythrocytes, and the pathology associated with this effect, by C Rice Evans. The oxidants produced by polymorphonuclear neutrophil cells: their mode of production and reaction, by CC Winterhoum. T--he role of oxygen radicals in pulmonary lesions induced by paraquat, by HJ Formann. The mechanisms of production of oxygen radicals in the syndrome of myocardial reperfusion ischemia, by DK Das and RM Engelman. The sources of oxygen radicals, detoxification systems and cancer cell membrane lesions, by T Galeotti, S Borello and L Masotti. The role of oxygen radicals in skeletal muscle lesions, by MJ Jackson. The role of oxygen radicals in central nervous system lesions and brain functions, by WB Essman and SB Wollman. Each of these general reviews includes a large number of references - over 100 in most chapters - which in itself makes this work valuable as a highly complete bibliographic source on the subject. It is regretable, however; and this may be due to publication delays, that most of the references date from before 1987. This would explain why some important but more recent findings, such as the cloning of the b558 cytochrome gene, a major component of the NADPH oxidase complex of phagocytic cells by Segal's group and the identification of the cytosolic factors involved in cellular oxidative metabolic activation, by the groups of Pick and Vignais are not mentioned in the chapter on neutrophils. Indeed, these findings have led to better characterization of the nature of the genetic defect at the origin of chronic granulomatous disease (CGD) in its form linked to the X chromosome and to the proposition of a new classification of other forms of CGD. In this respect the limited amount of
Trichoderma reesei Cellulases, Biochemistry, Genetics, Physiology and Applications, edited by CP Kubicek, DE Eveleigh,
H Esterbauer, W Steiner, EM Kubicek-Pranz. The Royal Society of Chemistry, 1990, 250 p, £ 42.50, US$ 82.00 Cellulose is the most abundant carbohydrate produced by plants. As such, the degradation of cellulose is therefore a major component of the carbon cycle. Enzymatic hydrolysis of cellulosic
substrates is far from straightforward, and requires the synergistic interaction of enzymes of various specificity. The study of cellulolytic systems therefore represents an important aspect of basic microbiology and biochemistry. At the peak of the oil crisis in the late 70"s, the biological conversion of cellulosic biomass into fuel and chemicals appeared to be a means of alleviating the energy crisis. Decreasing oil prices and a more realistic assessment of the technical difficulties involved have since made that goal a more remote possibility, even if more limited applications of cellulases are still being considered (eg silage treatment, fruit juice recovery, addition to laundry detergents). Nevertheless, cellulase research is making rapid progress, as shown by the number of interesting meetings held on the subject. This book contains the Proceedings of a meeting held in September 1989 in Vienna on Trichoderma reesei cellulases. That cellulose is indeed a valuable resource should be obvious from the fact that manuscripts originally typed on A-I camera-ready forms were printed half-size. However, any reader interested in cellulases, and endowed with sufficient visual acuity, will be rewarded for his efforts. T reesei has been the most extensively studied celh:iolytic organism since World War II. Not surprisingly, T reesei cellulase has become a reference system, even if it may turn out not to be representative of all cellulales (eg cellulases from anaerobic bacteria). This book comes at a time when the introduction of gene technology to the field is past the first excitement of cloning for its own sake, and biologically relevant questions can be approached with regard to structure-function relationships and regulation. As indicated in the title, the book covers various aspects of Trichoderma cellulase research. The part dealing with the regulation of cellulase synthesis (the paper by El Gogary et al: 'Trichoderma reesei cellulase - from mutants to induction' would belong to that section), is excellent. Kubicek et al give a clear overview of the evidence that cellulase induction most likely involves low molecular weight inducers which are generated from cellulose by constitutive levels of cellulolytic enzymes. The exact mechanism by which the inducers are produced and their chemical nature is not yet clear, however. Likewise, structural and molecular biology aspects are covered by very good presentations. The paper by Henrissat and Mornon on structural homologies between cellulases of various origins should become an obligate reference for anyone embarking on the comparison of cellulase sequences. The article by Teeri et a! shows that the stage is now set for the rational genetic engineering of T reesei cellulases. The structure of the catalytic core of cellobiohydrolase II has been elucidated by X-ray crystallography, and the structure of the cellulose-binding domain has been determined by NMR spectroscopy. Furthermore, a procedure has been developed for the transformation of T reesei, allowing targetted genetic manipulation of the organism. Papers dealing with production and applications are inevitably more descriptive and empirical, and will appear more arduous to the reader who is not directly involved in these aspects, although there is a good discussion of Trichoderma harzianum xylanases by Senior and Saddler. An important point, which is discussed by Teeri et al, is the fact that T reesei, like other filamentous fungi, has a tremendous capacity for secreting proteins. It would thus be a very promising host for expressing rDNA-encoded proteins. Efforts toward this goal have led to the construction of T reesei expression vectors based on fusion with the cbhl, however, and more research will be needed to exploit the full potential of T reesei as a cloning host. The weakest part of the book is the section dealing with the enzymology of T reesei cellulases. After 40 years of research, several aspects are still in a state of confusing controversy. The book contains no view of enzymology problems to match the excellent article of Kubicek et al on regulatory aspects.
901 On the whole, this book gives a concise and up-to-date presentation of the status of research on T reesei cellulases, and should be a valuable purchase for anyone interested in cellulose bioconversion, particularly the basic aspects. P Brguin
The Bacterial Chromosome, edited by K Drlica, M Riley. American Society for Microbiology, 1989, xvi + 469 pp, US$ 63.000 members; US$ 87.00 - non-members
ASM Publications are generally reference books, 'bibles' for scientists in the field they cover. Two recent publications MobileDNA edited by D Berg and M Howe, and The Bacterial Chromosome edited by K Drlica and M Riley deserve special attention. In fact, these books will be useful to scientists not only working in the field of bacterial genetics, but also in all fields involving molecular enetics. This is obvious for DNA mobile elements, since they were discovered by B McClintock in maize, but it is also true for the bacterial chromosome, the structure of which might suggest new concepts in several areas, encompassing structures and dynamics of gene expression. Mobile DNA is present in most, if not all, life forms and although several types of structures can be described (bacteriophages, retroviruses, transposons, insertion sequences, retroposons, retrotransposons) these DNA genes have much in common. Among the 43 papers that constitute the book, one can distinguish between structural, basic, or applied features of mobile DNA. Processes of transposition and insertion are well described, and plenty of references permit identification of important papers in the field. Specific examples are detailed both at the physiological and molecular levels (lambda, Mu, Tn3, Tn5, Tn7, Tnl0). In a series of transition chapters, more exotic organisms such as streptomycetes or holobacteria are reviewed from the point of view of mobile DNA. Agrobacteria permit a shift to be made from procaryotes to eucaryotes, where we begin to discover transposable elements and their effects in nucleated cells. Hybrid dysgenesis in Drosophila permits us to enter in more detail the field of phylogenesis. Retroposons, retrotransposons and repeated DNA are discussed at length and hundreds of references are given, thus permitting the relatively uniformed reader easily to become familiar with the field. The last chapters of this volume are devoted to genome unstabilities resulting from transposition, illegatimate recombination, rearrangements, inversions etc in a wide variety of organisms (fungi, bacteria, trypanosomes, mammalian cells). It is impossible to give a fair account of the immense wealth of data presented in this book. Clearly, all scientists who one day or another may have to consider DNA as a research object of choice should have mobile DNA readily available on their desks. The Bacterial Chromosome, edited by K Drlica and M Riley, is another ASM publication that also deserves much success. Like the preceeding book, but even more easily (because it is of a much smaller format), it could well be stolen from those who are fortunate enough to have it at hand. The book comprises 6 main parts dealing with primary, secondary and tertiary structures of DNA, as well as chromosome replication and segregation or major rearrangements; the last 2 parts are devoted to side issues: the global responses to stress and cryptic genetic information. Fifty years of research on bacteria have produced a fairly comprehensive picture of the bacterial chromosome, and it is now time to give a thorough description of its structure and the initiation and
termination of its replication. The book provides most of the recent literature dealing with the subject, and scientists will find many new insights from the consideration of the whole chromosome rather considered: sporulation ends up with a compact chromosome, thus its study is understandable in the present context, but heatshock seems more indirect... More indirect information comes from the study of the E coli chromosome map by Kohara. This author describes only 450 kbp of DNA as already sequenced, ignoring a very large amount of DNA present in international libraries: this indicates that the Japanese program of E coli chromosome sequencing might be much less advanced that usually assumed. Alternatively, the opposite might be the case and a large amount of DNA could be sequenced! In any case, the book is extremely valuable and will be interesting for all bacteriologists. AL Lecocq
Oxygen Radicals: Systemic Events and Disease Processes. Edited by DK Das, WB Essman, Karger, 1990, xii +196 p, SFr 174 ($116). This book gives an interesting general review of the role of oxygen radicals in the various pathophysiological states in which they are involved. Its 196 pages comprise 7 chapters written by various authors, most, if not all of whom are recognized experts in their fields. Each chapters is itself a general review, including a historical summary and a well-documented analysis of the main fundamental and clinical studies which led to the description of the production and mechanism of action of oxygen radicals towards their targets. The following topics are treated successively. The effect of oxygen radicals on erythrocytes, and the pathology associated with this effect, by C Rice Evans. The oxidants produced by polymorphonuclear neutrophil cells: their mode of production and reaction, by CC Winterhoum. T--he role of oxygen radicals in pulmonary lesions induced by paraquat, by HJ Formann. The mechanisms of production of oxygen radicals in the syndrome of myocardial reperfusion ischemia, by DK Das and RM Engelman. The sources of oxygen radicals, detoxification systems and cancer cell membrane lesions, by T Galeotti, S Borello and L Masotti. The role of oxygen radicals in skeletal muscle lesions, by MJ Jackson. The role of oxygen radicals in central nervous system lesions and brain functions, by WB Essman and SB Wollman. Each of these general reviews includes a large number of references - over 100 in most chapters - which in itself makes this work valuable as a highly complete bibliographic source on the subject. It is regretable, however; and this may be due to publication delays, that most of the references date from before 1987. This would explain why some important but more recent findings, such as the cloning of the b558 cytochrome gene, a major component of the NADPH oxidase complex of phagocytic cells by Segal's group and the identification of the cytosolic factors involved in cellular oxidative metabolic activation, by the groups of Pick and Vignais are not mentioned in the chapter on neutrophils. Indeed, these findings have led to better characterization of the nature of the genetic defect at the origin of chronic granulomatous disease (CGD) in its form linked to the X chromosome and to the proposition of a new classification of other forms of CGD. In this respect the limited amount of