Eto M, Senba S, Morita F, Yazawa M
Division of Chemistry, Graduate School of Science, Hokkaido University, Sapporo, Japan.
FEBS Lett. 1997 Jun 30;410(2-3):356-60. doi: 10.1016/s0014-5793(97)00657-1.
The cDNA encoding a phosphorylation-dependent inhibitory protein of protein phosphatase-1 (PP1) was isolated from a porcine aorta library. The coding region represented the complete amino acid sequence of this protein comprised of a novel 147-residue polypeptide, which we termed CPI17, a 17-kDa PKC-potentiated inhibitory protein of PP1. As well as the native CPI17 from porcine aorta, the recombinant protein completely suppressed the PP1 activity (IC50 = 0.18 nM) by the stoichiometric thiophosphorylation. The CPI17 mRNA is expressed in smooth muscle tissues such as aorta and bladder, whereas little expression was observed in heart, skeletal muscle, and non-muscle tissues. These results suggest a specific regulatory mechanism of the PP1 activity through CPI17 in smooth muscle.
从猪主动脉文库中分离出编码蛋白磷酸酶-1（PP1）磷酸化依赖性抑制蛋白的cDNA。编码区代表了该蛋白完整的氨基酸序列，其由一个新的147个残基的多肽组成，我们将其命名为CPI17，这是一种17 kDa的蛋白激酶C增强的PP1抑制蛋白。与来自猪主动脉的天然CPI17一样，重组蛋白通过化学计量的硫代磷酸化完全抑制了PP1活性（IC50 = 0.18 nM）。CPI17 mRNA在主动脉和膀胱等平滑肌组织中表达，而在心脏、骨骼肌和非肌肉组织中几乎没有表达。这些结果表明平滑肌中存在通过CPI17对PP1活性的特定调节机制。
