Two splice variants of a tyrosine phosphatase differ in substrate specificity, DNA binding, and subcellular location

Kamatkar, Shubhangi ; Radha, Vegesna ; Nambirajan, S. ; Sreekantha Reddy, R. ; Swarup, Ghanshyam (1996) Two splice variants of a tyrosine phosphatase differ in substrate specificity, DNA binding, and subcellular location Journal of Biological Chemistry, 271 . pp. 26755-26761. ISSN 0021-9258

Full text not available from this repository.

Official URL: http://www.jbc.org/content/271/43/26755.short

Related URL: http://dx.doi.org/10.1074/jbc.271.43.26755

Abstract

Four different forms of a non-receptor type protein-tyrosine phosphatase are generated by alternative splicing; two of these forms (PTP-S2 and PTP-S4) are major forms, which are expressed in rat as well as human cells. Here we report that PTP-S2 binds to nonspecific DNA in vitro and localizes in the nucleus upon transfection in HeLa cells. PTP-S4 does not bind to nonspecific DNA and shows perinuclear and cytoplasmic localization. Removal of the C-terminal 34 amino acids of PTP-S4 gives rise to a truncated protein, which binds to nonspecific DNA and localizes to the nucleus. PTP-S4, but not PTP-S2, interacts strongly with the isolated nuclear matrix. The two forms of this tyrosine phosphatase show different substrate specificity in vitro, a feature novel to splice variants of tyrosine phosphatases. Mitogenic stimulation induces mRNAs for PTP-S2 as well as for PTP-S4 in the G1 phase during liver regeneration. These results suggest that alternative splicing gives rise to two protein-tyrosine phosphatases with distinct substrate specificities and subcellular locations. The 34 amino acids at the C terminus of PTP-S4 play a critical role in determining substrate specificity, subcellular location, and interaction with nuclear matrix and DNA.

Item Type:Article
Source:Copyright of this article belongs to The American Society for Biochemistry and Molecular Biology.
ID Code:54450
Deposited On:11 Aug 2011 10:48
Last Modified:11 Aug 2011 10:48

Repository Staff Only: item control page