Cloning of murine low molecular weight phosphotyrosine protein phosphatase cDNA: identification of a new isoform

FEBS Letters

Camici, G¹  Giannoni, E¹  Cirri, P¹  Modesti, A¹  Paoli, P¹  Raugei, G¹  Magherini, F¹  Ramponi, G¹ 

[1] Dipartimento di Scienze Biochimiche, Università di Firenze, viale Morgagni 50, 50134 Florence, Italy

关键词: Phosphotyrosine protein phosphatase;    Alternative splicing;    Mouse;    LMW-PTP;    low molecular weight phosphotyrosine protein phosphatase;    PTPs;    protein tyrosine phosphatases;    PTKs;    protein tyrosine kinases;    ERK;    extracellular signal-regulated kinase;    STAT;    signal transducer and activators of transcription;    pNPP;    para-nitrophenyl phosphate;    RACE;    rapid amplification of cDNA ends;   

DOI  :  10.1016/S0014-5793(98)01241-1

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The low molecular weight phosphotyrosine protein phosphatase (LMW-PTP) is a 18 kDa cytosolic enzyme, involved in the negative regulation of cell proliferation. In different mammalian species LMW-PTPs are expressed in two molecular forms produced from a single primary transcript through an alternative splicing mechanism. In this paper we report the cloning, expression and characterization of mouse isoforms of LMW-PTPs (called m-IF1 and m-IF2), very similar to the corresponding rat and human isoenzymes. Moreover we have identified a third cDNA encoding a protein (m-IF2P) that presents three substitutions compared to m-IF2. This new isoform is still active on pNPP, although to a lower extent: this reduction is mainly due to the leucine to proline substitution in position 13, within the catalytic loop. The mRNA expression level of this isoform is comparable to those of m-IF1 and m-IF2. It is likely that a gene duplication process followed by mutations has generated this new gene.

【 授权许可】

Unknown