Characterization of the interactions between inhibitor-1 and recombinant PP1 by NMR spectroscopy

Chu Ting Liang, Yu Shan Lin, Yi Choang Huang, Hsien Lu Huang, Jia Qian Yang, Tsung Hsien Wu, Chi Fon Chang, Shing Jong Huang, Hsien Bin Huang, Ta Hsien Lin*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

2 Scopus citations

Abstract

Inhibitor-1 is converted into a potent inhibitor of native protein phosphatase-1 (PP1) when Thr35 is phosphorylated by cAMP-dependent protein kinase (PKA). However, PKA-phosphorylated form of inhibitor-1 displayed a weak activity in inhibition of recombinant PP1. The mechanism for the impaired activity of PKA-phosphorylated inhibitor-1 toward inhibition of recombinant PP1 remained elusive. By using NMR spectroscopy in combination with site-directed mutagenesis and inhibitory assay, we found that the interaction between recombinant PP1 and the consensus PP1-binding motif of PKA-thiophosphorylated form of inhibitor-1 was unexpectedly weak. Unlike binding to native PP1, the subdomains 1 (residues around and including the phosphorylated Thr35) and 2 (the consensus PP1-binding motif) of PKA-thiophosphorylated form of inhibitor-1 do not exhibit a synergistic effect in inhibition of recombinant PP1. This finding implied that a slight structural discrepancy exists between native and recombinant PP1, resulting in PKA-thiophosphorylated form of inhibitor-1 displaying a different affinity to native and recombinant enzyme.

Original languageEnglish
Article number50
JournalScientific reports
Volume8
Issue number1
DOIs
StatePublished - 1 Dec 2018

Fingerprint

Dive into the research topics of 'Characterization of the interactions between inhibitor-1 and recombinant PP1 by NMR spectroscopy'. Together they form a unique fingerprint.

Cite this