help button home button Genetics Science
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Originally published as Genetics Published Articles Ahead of Print on August 24, 2007.

Genetics, Vol. 177, 959-970, October 2007, Copyright © 2007
doi:10.1534/genetics.107.075846

This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Data Supplement
Right arrow All Versions of this Article:
genetics.107.075846v1
177/2/959    most recent
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Bussink, A. P.
Right arrow Articles by Boot, R. G.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Bussink, A. P.
Right arrow Articles by Boot, R. G.

Evolution of Mammalian Chitinase(-Like) Members of Family 18 Glycosyl Hydrolases

Anton P. Bussink, Dave Speijer, Johannes M. F. G. Aerts and Rolf G. Boot1

Department of Medical Biochemistry, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands

1 Corresponding author: Department of Medical Biochemistry, Academic Medical Center, University of Amsterdam, Meibergdreef 15, 1105 AZ Amsterdam, The Netherlands.
E-mail: r.g.boot{at}amc.uva.nl

Family 18 of glycosyl hydrolases encompasses chitinases and so-called chi-lectins lacking enzymatic activity due to amino acid substitutions in their active site. Both types of proteins widely occur in mammals although these organisms lack endogenous chitin. Their physiological function(s) as well as evolutionary relationships are still largely enigmatic. An overview of all family members is presented and their relationships are described. Molecular phylogenetic analyses suggest that both active chitinases (chitotriosidase and AMCase) result from an early gene duplication event. Further duplication events, followed by mutations leading to loss of chitinase activity, allowed evolution of the chi-lectins. The homologous genes encoding chitinase(-like) proteins are clustered in two distinct loci that display a high degree of synteny among mammals. Despite the shared chromosomal location and high homology, individual genes have evolved independently. Orthologs are more closely related than paralogues, and calculated substitution rate ratios indicate that protein-coding sequences underwent purifying selection. Substantial gene specialization has occurred in time, allowing for tissue-specific expression of pH optimized chitinases and chi-lectins. Finally, several family 18 chitinase-like proteins are present only in certain lineages of mammals, exemplifying recent evolutionary events in the chitinase protein family.






HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 2007 by the Genetics Society of America.