A force-activated kinase in a catch smooth muscle.
A force-activated kinase in a catch smooth muscle.
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DOI：
10.1007/s10974-011-9240-2
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发表时间：
2011-03
影响因子：
2.7
通讯作者：
Siegman, Marion J.
中科院分区：
文献类型：
--
作者：
Butler, Thomas M.;Siegman, Marion J.
来自紫贻贝的透化的前足丝牵开肌（ABRM）被用作一个简单的系统来测试是否存在对于肌联蛋白和迷你肌联蛋白twitchin所假设的激酶的牵张依赖性激活。ABRM是一种平滑肌，当细胞内Ca++浓度降低到次最大水平时，显示捕获，即刺激后高力维持和拉伸阻力的条件。在捕捉状态下，twitchin是未磷酸化的，并且肌肉在没有肌球蛋白跨桥的情况下保持力量，所述肌球蛋白跨桥循环通过可能是twitchin介导的粗细丝和细丝之间的系链。在接球中，长度的微小变化会导致力量的巨大变化。添加的肽的磷酸化状态，软体动物抽搐激酶的良好底物，序列KKRAARATSNVFA被用作激酶活化的量度。我们发现，有一个约2倍的增加，在磷酸化的添加肽与10%的拉伸的ABRM在捕捉。增加的磷酸化是由于激酶的激活而不是磷酸酶的抑制。当tickin被磷酸化并且捕获力不存在时，肽的磷酸化程度降低。然而，当肌肉在pCa 5中被激活时，肽磷酸化也有大量增加，并且捕获状态不存在。力敏激酶活性被作为tickin激酶抑制剂的ML-9和ML-7降低，但不被Rho激酶抑制剂Y-27632降低。肌球蛋白轻链没有可检测到的磷酸化，但肌颤蛋白的磷酸化随着拉伸增加了一个小的但显著的程度。可能的是，tickin感觉力输出，导致力敏感性tickin激酶活性，其导致tickin在除了负责捕获松弛的位点之外的位点上的自磷酸化。
Permeabilized anterior byssus retractor muscles (ABRM) from Mytilus edulis were used as a simple system to test whether there is a stretch dependent activation of a kinase as has been postulated for titin and the mini-titin twitchin. The ABRM is a smooth muscle that shows catch, a condition of high force maintenance and resistance to stretch following stimulation when the intracellular Ca++ concentration has diminished to sub-maximum levels. In the catch state twitchin is unphosphorylated, and the muscle maintains force without myosin crossbridge cycling through what is likely a twitchin mediated tether between thick and thin filaments. In catch, a small change in length results in a large change in force. The phosphorylation state of an added peptide, a good substrate for molluscan twitchin kinase, with the sequence KKRAARATSNVFA was used as a measure of kinase activation. We find that there is about a two-fold increase in phosphorylation of the added peptide with a 10% stretch of the ABRM in catch. The increased phosphorylation is due to activation of a kinase rather than to an inhibition of a phosphatase. The extent of phosphorylation of the peptide is decreased when twitchin is phosphorylated and catch force is not present. However, there is also a large increase in peptide phosphorylation when the muscle is activated in pCa 5, and the catch state does not exist. The force-sensitive kinase activity is decreased by ML-9 and ML-7 which are inhibitors of twitchin kinase, but not by the Rho kinase inhibitor Y-27632. There is no detectable phosphorylation of myosin light chains, but the phosphorylation of twitchin increases by a small, but significant extent with stretch. It is possible that twitchin senses force output resulting in a force-sensitive twitchin kinase activity that results in autophosphorylation of twitchin on site(s) other than those responsible for relaxation of catch.
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影响因子：
20.1
作者：
Hidalgo C;Hudson B;Bogomolovas J;Zhu Y;Anderson B;Greaser M;Labeit S;Granzier H
通讯作者：
Granzier H
影响因子：
3.4
作者：
Butler, TM;Mooers, SU;Siegman, MJ
通讯作者：
Siegman, MJ
DOI：
10.1016/j.bbapap.2009.12.020
发表时间：
2010-04-01
影响因子：
3.2
作者：
Matusovsky, Oleg S.;Shelud'ko, Nikolay S.;Sobieszek, Apolinary
通讯作者：
Sobieszek, Apolinary
影响因子：
3.4
作者：
Bianco, Pasquale;Nagy, Attila;Kellermayer, Miklos S. Z.
通讯作者：
Kellermayer, Miklos S. Z.
影响因子：
4.8
作者：
Amano, M;Ito, M;Kaibuchi, K
通讯作者：
Kaibuchi, K