The role of the calponin homology domain of smoothelin-like 1 (SMTNL1) in myosin phosphatase inhibition and smooth muscle contraction.
The role of the calponin homology domain of smoothelin-like 1 (SMTNL1) in myosin phosphatase inhibition and smooth muscle contraction.
复制标题
DOI：
10.1007/s11010-009-0047-z
复制
发表时间：
2009-07
影响因子：
4.3
通讯作者：
MacDonald, Justin A.
中科院分区：
文献类型：
--
作者：
Borman, Meredith A.;Freed, Tiffany A.;Haystead, Timothy A. J.;MacDonald, Justin A.
关键词：
在这项研究中，我们进一步深入了解了平滑素样1 （SMTNL1）钙钙蛋白同源性（CH）结构域对肌球蛋白轻链磷酸酶（SMPP-1M）活性和平滑肌收缩的贡献。SMTNL1蛋白对SMPP-1M活性有抑制作用，但对肌球蛋白轻链激酶（MLCK）活性无抑制作用。SMTNL1对pCa6.3溶液刺激兔回肠平滑肌达到一半最大力所需时间（t1/2）无影响。在渗透性平滑肌条中加入重组SMTNL1蛋白可显著降低收缩力。虽然钙钙蛋白同源性（CH）结构域对于smtnl1相关的最大松弛是必不可少的，但它本身并没有引起显著的力变化。在肌球蛋白靶向亚基（MYPT1）存在的情况下，PP-1C很难将SMTNL1去磷酸化，这表明磷酸化的SMTNL1不具有“底物捕获”特性。此外，全长SMTNL1可以在体外抑制SMPP-1M对LC20的活性，而缺失ch结构域的截断SMTNL1则无效。总之，我们的研究结果表明ch结构域在介导SMTNL1对平滑肌收缩的影响中起重要作用。
In this study, we provide further insight into the contribution of the smoothelin-like 1 (SMTNL1) calponin homology (CH)-domain on myosin light chain phosphatase (SMPP-1M) activity and smooth muscle contraction. SMTNL1 protein was shown to have inhibitory effects on SMPP-1M activity but not on myosin light chain kinase (MLCK) activity. Treatment of β-escin permeabilized rabbit, ileal smooth muscle with SMTNL1 had no effect on the time required to reach half-maximal force (t1/2) during stimulation with pCa6.3 solution. The addition of recombinant SMTNL1 protein to permeabilized, smooth muscle strips caused a significant decrease in contractile force. While the calponin homology (CH)-domain was essential for maximal SMTNL1-associated relaxation, it alone did not cause significant changes in force. SMTNL1 was poorly dephosphorylated by PP-1C in the presence of the myosin targeting subunit (MYPT1), suggesting that phosphorylated SMTNL1 does not possess “substrate trapping” properties. Moreover, while full-length SMTNL1 could suppress SMPP-1M activity toward LC20 in vitro, truncated SMTNL1 lacking the CH-domain was ineffective. In summary, our findings suggest an important role for the CH-domain in mediating the effects of SMTNL1 on smooth muscle contraction.
登录
查看更多内容
影响因子：
4
作者：
Quensel, C;Krämer, J;Leonhardt, H
通讯作者：
Leonhardt, H
影响因子：
5.5
作者：
Zhang, WW;Wu, YD;Gunst, SJ
通讯作者：
Gunst, SJ
DOI：
10.1073/pnas.88.20.9307
发表时间：
1991-10-01
影响因子：
11.1
作者：
KITAZAWA, T;MASUO, M;SOMLYO, AP
通讯作者：
SOMLYO, AP
影响因子：
20.1
作者：
Nakamura, Kensei;Koga, Yasuhiko;Ikebe, Mitsuo
通讯作者：
Ikebe, Mitsuo
影响因子：
4.8
作者：
Wu, XQ;Haystead, TAJ;Somlyo, AP
通讯作者：
Somlyo, AP