QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

First published online October 22, 2008

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Related articles in JCS Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Search for Related Content Social Bookmarking                         What's this?

Cbl – taking on a phosphatase

Receptor tyrosine kinases (RTKs) trigger several cell signalling pathways (particularly those that regulate cell proliferation, motility and survival), so their activity must be tightly regulated. In metazoa, Cbl proteins downregulate RTKs by ubiquitinating them and targeting them for degradation, but it is not known whether they have other roles in less-complex organisms. On page 3524, Jeffrey Williams and colleagues identify CblA, the first non-metazoan Cbl protein, in the facultative multicellular organism Dictyostelium discoideum and characterise its function. In a cblA-null strain of Dictyostelium, they show, multicellular slugs fragment along their length and fail to form a normal basal disc. Notably, this phenotype is echoed in Dictyostelium strains that are deficient in signalling by DIF-1 (which normally signals through STATc to promote the differentation of Dictyostelium into stalk and pre-stalk cells). The authors show that DIF-inducible tyrosine phosphorylation of STATc is downregulated in cblA-null cells, whereas the protein tyrosine phosphatase PTP3B is present at a higher concentration. The authors conclude that, similar to DIF-1, CblA activates STATc by acting as a negative regulator of PTP3B. Thus, metazoan Cbl proteins regulate tyrosine kinases, but the Dictyostelium Cbl homologue acts on a tyrosine phosphatase.

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?

Related articles in JCS:

A Dictyostelium homologue of the metazoan Cbl proteins regulates STAT signalling

Judith Langenick, Tsuyoshi Araki, Yoko Yamada, and Jeffrey G. Williams
JCS 2008 121: 3524-3530. [Abstract] [Full Text]  

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Related articles in JCS Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Search for Related Content Social Bookmarking                         What's this?