Novel 130-kDa rat liver myosin-1 will translocate actin filaments.
Novel 130-kDa rat liver myosin-1 will translocate actin filaments.
复制标题
新型 130 kDa 大鼠肝脏肌球蛋白-1 将使肌动蛋白丝易位。
DOI：
10.1002/cm.970270105
复制
发表时间：
1994
影响因子：
--
通讯作者：
Coluccio,LM
中科院分区：
文献类型：
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作者：
Williams,R;Coluccio,LM
我们最近从大鼠肝脏中纯化并表征了具有肌球蛋白-1的几个特征的110-kDa和130-kDa的多肽[Coluccio和Conaty：Cell Motil. Cytoskeleton 24：189-199，1993]。这些肌球蛋白-1分子在肝细胞中发挥的作用尚未确定。一种假设是它们参与细胞内运输或运动。作为建立其功能的第一步，我们研究了这些分子是否能够在体外支持运动。我们的结果清楚地表明，分离的130-kDa-钙调素复合物将以0.03-0.05 μ/sec的速率移位细丝;在游离钙离子浓度高于0.1 μM时，运动受到抑制。这种抑制作用可通过加入外源性钙调素而逆转。这些结果为130 kDa-钙调素复合物在体内的能动作用提供了支持证据。这是第一次证明，在高等真核生物中，来自肠以外组织的肌球蛋白-1将支持运动。部分肽序列分析表明，130-kDa多肽类似于最近描述的myr 1 [Ruppert等人：J. Cell Biol.120：1393-1403，1993]或MM 1 α [Sherr等人：1405-1416，1993]基因产物© 1994 Wiley-Liss，Inc.
We have recently purified and characterized from rat liver, polypeptides of 110-kDa and 130-kDa which possess several characteristics of myosin-1 [Coluccio and Conaty: Cell Motil. Cytoskeleton 24: 189-199, 1993]. What roles these myosin-1 molecules play in hepatocytes is not yet defined. One hypothesis is that they are involved in either intracellular transport or locomotion. As a first step in establishing their function, we have investigated whether these molecules are capable of supporting motility in vitro. Our results clearly demonstrate that the isolated 130-kDa-calmodulin complex will translocate filaments at a rate of 0.03-0.05 μ/sec; motility is inhibited in free calcium ion concentrations above 0.1 μM. This inhibition is reversed with the addition of exogenous calmodulin. These results provide supporting evidence of a motile role for the 130-kDa-calmodulin complex in vivo. This is the first demonstration that in higher eukaryotes, myosin-1 from a tissue other than intestine will support motility. Partial peptide sequence analysis indicates that the 130-kDa polypeptide resembles the recently described myr 1 [Ruppert et al.: J. Cell Biol. 120: 1393-1403, 1993] or MM1α [Sherr et al.: J. Cell Biol. 1405-1416, 1993] gene product.© 1994 Wiley-Liss, Inc.