Regulation of neurabin I interaction with protein phosphatase 1 by phosphorylation.

TitleRegulation of neurabin I interaction with protein phosphatase 1 by phosphorylation.
Publication TypeJournal Article
Year of Publication1999
AuthorsMcAvoy T, Allen PB, Obaishi H, Nakanishi H, Takai Y, Greengard P, Nairn AC, Hemmings HC
Date Published1999 Sep 28
KeywordsAmino Acid Sequence, Animals, Brain, Cyclic AMP-Dependent Protein Kinases, Male, Microfilament Proteins, Molecular Sequence Data, Nerve Tissue Proteins, Peptide Fragments, Phosphoprotein Phosphatases, Phosphorylation, Precipitin Tests, Protein Phosphatase 1, Rats, Rats, Sprague-Dawley, Sequence Homology, Amino Acid

Neurabin I is a brain-specific actin-binding protein. Here we show that neurabin I binds protein phosphatase 1 (PP1) and inhibits PP1 activity. Neurabin I interacted with PP1alpha in an overlay assay, in yeast two-hybrid interaction analysis, and in coprecipitation and co-immunoprecipitation experiments. Neurabin I also copurified with both the alpha and gamma isoforms of PP1. A glutathione S-transferase (GST)-neurabin I fusion protein (residues 318-661) containing the putative PP1 binding domain (residues 456-460) inhibited PP1 activity (K(i) = 2.7 +/- 1.2 nM). This fusion protein was also rapidly phosphorylated in vitro by PKA (K(m) = 6 microM) to a stoichiomtry of 1 mol/mol. The phosphorylated residue was identified as serine 461 by HPLC-MS analysis of a tryptic digest. Phosphorylation of GST-neurabin I (residues 318-661) by PKA significantly reduced its binding to PP1 by overlay and by glutathione-Sepharose coprecipitation assays. A 35-fold decrease in inhibitory potency was also observed using a S461E mutant, which mimics phosphorylation of S461. These findings identify a signaling mechanism involving the regulation of PP1 activity and localization mediated by the cAMP pathway.

Alternate JournalBiochemistry
PubMed ID10504266
Grant ListDA10044 / DA / NIDA NIH HHS / United States
MH40899 / MH / NIMH NIH HHS / United States
P01 DA010044 / DA / NIDA NIH HHS / United States