Dissociation of SHP-1 from spinophilin during platelet activation exposes an inhibitory binding site for protein phosphatase-1 (PP1).
Dissociation of SHP-1 from spinophilin during platelet activation exposes an inhibitory binding site for protein phosphatase-1 (PP1).
复制标题
DOI：
10.1371/journal.pone.0119496
复制
发表时间：
2015
期刊：
影响因子：
3.7
通讯作者：
Brass LF
中科院分区：
文献类型：
--
作者：
Ma P;Foote DC;Sinnamon AJ;Brass LF
We have recently shown that a critical regulatory node in the platelet signaling network lies immediately downstream of platelet receptors for thrombin and TxA2. This node is comprised of a scaffold protein (spinophilin, SPL), a protein tyrosine phosphatase (SHP-1), and either of the two members of the Regulators of G protein Signaling family predominantly expressed in platelets (RGS10 or RGS18). The SPL/RGS/SHP-1 complex is present in resting platelets, dissociating when thrombin or TxA2, but not ADP or collagen, activate SHP-1 and release RGS10 and RGS18 to dampen signaling. Here we demonstrate an additional regulatory role for spinophilin, showing that dissociation of SHP-1 from spinophilin is followed by an increase in the binding of spinophilin to PP1, a serine/threonine phosphatase whose binding site maps to a region close to the SHP-1 binding site. The increase in PP1 binding to spinophilin is limited to platelet agonists that cause dissociation of the complex and is selective for the α and γ isoforms of PP1. Studies in cell culture show that SHP-1 and PP1 can compete for binding to spinophilin and that binding inhibits PP1 activity since over-expression of wild type spinophilin, but not spinophilin with a disabled PP1 binding site, causes an increase in the phosphorylation of myosin light chain, a well-characterized PP1 substrate. Collectively, these results indicate that in addition to regulating RGS protein availability in resting platelets, spinophilin can serve as a time-dependent, agonist- and isoform-selective regulator of PP1, inhibiting its activity when decay of the SPL/RGS/SHP-1 complex releases SHP-1 from spinophilin, exposing a binding site for PP1.
登录
查看更多内容
影响因子：
2.9
作者：
Hsieh-Wilson, LC;Allen, PB;Greengard, P
通讯作者：
Greengard, P
影响因子：
20.3
作者：
Gegenbauer, Kristina;Elia, Giuliano;Smolenski, Albert
通讯作者：
Smolenski, Albert
影响因子：
4.8
作者：
Carmody, Leigh C.;Baucum, Anthony J., II;Colbran, Roger J.
通讯作者：
Colbran, Roger J.
影响因子：
16.8
作者：
通讯作者：
--
影响因子：
20.3
作者：
Rowley, Jesse W.;Oler, Andrew J.;Weyrich, Andrew S.
通讯作者：
Weyrich, Andrew S.