Molecular cloning and sequence analysis of expansins - A highly conserved, multigene family of proteins that mediate cell wall extension in plants

Tatyana Y. Shcherban, Jun Shi, Daniel M. Durachko, Mark J. Guiltinan, Simon J. Mcqueen-Mason, Mark Shieh, Daniel J. Cosgrove

Research output: Contribution to journalArticlepeer-review

200 Scopus citations

Abstract

Expansins are unusual proteins discovered by virtue of their ability to mediate cell wall extension in plants. We identified cDNA clones for two cucumber expansins on the basis of peptide sequences of proteins purified from cucumber hypocotyls. The expansin cDNAs encode related proteins with signal peptides predicted to direct protein secretion to the cell wall. Northern blot analysis showed moderate transcript abundance in the growing region of the hypocotyl and no detectable transcripts in the nongrowing region. Rice and Arabidopsis expansin cDNAs were identified from collections of anonymous cDNAs (expressed sequence tags). Sequence comparisons indicate at least four distinct expansin cDNAs in rice and at least six in Arabidopsis. Expansins are highly conserved in size and sequence (60-87% amino acid sequence identity and 75-95% similarity between any pairwise comparison), and phylogenetic trees indicate that this multigene family formed before the evolutionary divergence of monocotyledons and dicotyledons. Sequence and motif analyses show no similarities to known functional domains that might account for expansin action on wall extension. A series of highly conserved tryptophans may function in expansin binding to cellulose or other glycans. The high conservation of this multigene family indicates that the mechanism by which expansins promote wall extension tolerates little variation in protein structure.

Original languageEnglish (US)
Pages (from-to)9245-9249
Number of pages5
JournalProceedings of the National Academy of Sciences of the United States of America
Volume92
Issue number20
DOIs
StatePublished - Sep 26 1995

All Science Journal Classification (ASJC) codes

  • General

Fingerprint Dive into the research topics of 'Molecular cloning and sequence analysis of expansins - A highly conserved, multigene family of proteins that mediate cell wall extension in plants'. Together they form a unique fingerprint.

Cite this