Skip Header

You are using a version of browser that may not display all the features of this website. Please consider upgrading your browser.

Protein phosphatase with EF-hand domains 2 (PPEF2) is a potent negative regulator of apoptosis signal regulating kinase-1 (ASK1).

Kutuzov M.A., Bennett N., Andreeva A.V.

The function of protein phosphatases with EF-hand domains (PPEF) in mammals is not known. Large-scale expression profiling experiments suggest that PPEF expression may correlate with stress protective responses, cell survival, growth, proliferation, or neoplastic transformation. Apoptosis signal regulating kinase-1 (ASK1) is a MAP kinase kinase kinase implicated in cancer, cardiovascular and neurodegenerative diseases. ASK1 is activated by oxidative stress and induces pro-apoptotic or inflammatory signalling, largely via sustained activation of MAP kinases p38 and/or JNK. We identify human PPEF2 as a novel interacting partner and a negative regulator of ASK1. In COS-7 or HEK 293A cells treated with H(2)O(2), expression of PPEF2 abrogated sustained activation of p38 and one of the JNK p46 isoforms, and prevented ASK1-dependent caspase-3 cleavage and activation. PPEF2 efficiently suppressed H(2)O(2)-induced activation of ASK1. Overexpessed as well as endogenous ASK1 co-immunoprecipitated with PPEF2. PPEF2 was considerably more potent both as a suppressor of ASK1 activation and as its interacting partner as compared to protein phosphatase 5 (PP5), a well-known negative regulator of ASK1. PPEF2 was found to form complexes with endogenous Hsp70 and to a lesser extent Hsp90, which are also known interacting partners of PP5. These data identify, for the first time, a possible downstream signalling partner of a mammalian PPEF phosphatase, and suggest that, despite structural divergence, PPEF and PP5 phosphatases may share common interacting partners and functions.

Int. J. Biochem. Cell Biol. 42:1816-1822(2010) [PubMed] [Europe PMC]

We'd like to inform you that we have updated our Privacy Notice to comply with Europe’s new General Data Protection Regulation (GDPR) that applies since 25 May 2018.

Do not show this banner again
UniProt is an ELIXIR core data resource
Main funding by: National Institutes of Health