Partial deduced sequence of the 110-kD-calmodulin complex of the avian intestinal microvillus shows that this mechanoenzyme is a member of the myosin I family.
Partial deduced sequence of the 110-kD-calmodulin complex of the avian intestinal microvillus shows that this mechanoenzyme is a member of the myosin I family.
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DOI：
10.1083/jcb.109.6.2895
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发表时间：
1989-12
期刊：
影响因子：
--
通讯作者：
Arpin M
中科院分区：
文献类型：
--
作者：
Garcia A;Coudrier E;Carboni J;Anderson J;Vandekerkhove J;Mooseker M;Louvard D;Arpin M
肠刷状缘的每个微绒毛内的肌动蛋白束通过由蛋白质复合物110-kD-钙调蛋白组成的桥横向拴系到膜上。以往的研究表明，鸟类110-kD-钙调素与肌球蛋白有许多共同的性质，包括机械化学活性。在本研究中，编码1,000个氨基酸的110-kD蛋白质的cDNA分子已被测序，提供了直接的证据表明，这种蛋白质是一个脊椎动物的同源物的无尾，单头肌球蛋白I首先描述在变形虫细胞。110-kD蛋白（或刷状缘肌球蛋白I重链）的一级结构由两个结构域组成，氨基末端“头”结构域和35-kD羧基末端“尾”结构域。头部结构域与其它已知肌球蛋白的S1结构域同源，在阿米巴肌球蛋白IB的头部结构域与由牛肌球蛋白I重链基因编码的蛋白质的S1结构域之间观察到最高同源性（MIHC; Hoshimaru，M.，和S.中西1987. J.Biol.Chem.262：14625- 14632）。羧基末端结构域显示没有显着的同源性与任何其他已知的肌球蛋白，除了牛MIHC。这表明牛MIHC基因最可能编码牛刷状缘肌球蛋白I（BBMI）的重链。由刷状缘110-kD cDNA编码的细菌表达的融合蛋白结合钙调蛋白。蛋白水解去除融合蛋白的羧基末端结构域导致钙调素结合活性的丧失，这一结果与先前对110 kD蛋白的结构域结构的研究一致。分子中不存在疏水序列，表明鸡BBMI重链可能不是完整的膜蛋白。各种鸡组织的北方印迹分析表明BBMI重链优先在肠中表达。
The actin bundle within each microvillus of the intestinal brush border is laterally tethered to the membrane by bridges composed of the protein complex, 110-kD-calmodulin. Previous studies have shown that avian 110-kD-calmodulin shares many properties with myosins including mechanochemical activity. In the present study, a cDNA molecule encoding 1,000 amino acids of the 110-kD protein has been sequenced, providing direct evidence that this protein is a vertebrate homologue of the tail-less, single-headed myosin I first described in amoeboid cells. The primary structure of the 110-kD protein (or brush border myosin I heavy chain) consists of two domains, an amino-terminal "head" domain and a 35-kD carboxy-terminal "tail" domain. The head domain is homologous to the S1 domain of other known myosins, with highest homology observed between that of Acanthamoeba myosin IB and the S1 domain of the protein encoded by bovine myosin I heavy chain gene (MIHC; Hoshimaru, M., and S. Nakanishi. 1987. J. Biol. Chem. 262:14625- 14632). The carboxy-terminal domain shows no significant homology with any other known myosins except that of the bovine MIHC. This demonstrates that the bovine MIHC gene most probably encodes the heavy chain of bovine brush border myosin I (BBMI). A bacterially expressed fusion protein encoded by the brush border 110-kD cDNA binds calmodulin. Proteolytic removal of the carboxy-terminal domain of the fusion protein results in loss of calmodulin binding activity, a result consistent with previous studies on the domain structure of the 110-kD protein. No hydrophobic sequence is present in the molecule indicating that chicken BBMI heavy chain is probably not an integral membrane protein. Northern blot analysis of various chicken tissue indicates that BBMI heavy chain is preferentially expressed in the intestine.
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影响因子：
11.4
作者：
COUDRIER, E;REGGIO, H;LOUVARD, D
通讯作者：
LOUVARD, D
DOI：
10.1083/jcb.108.2.495
发表时间：
1989-02
期刊：
The Journal of cell biology
影响因子：
--
作者：
Coluccio LM;Bretscher A
通讯作者：
Bretscher A
影响因子：
56.9
作者：
BURN, P;BURGER, MM
通讯作者：
BURGER, MM
影响因子：
7.8
作者：
COLUCCIO, LM;BRETSCHER, A
通讯作者：
BRETSCHER, A
影响因子：
64.8
作者：
HIGGINS, CF;HILES, ID;HERMODSON, MA
通讯作者：
HERMODSON, MA