Biochemical and bioinformatic analysis of the myosin-XIX motor domain.
Biochemical and bioinformatic analysis of the myosin-XIX motor domain.
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DOI：
10.1002/cm.21110
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发表时间：
2013-05
期刊：
影响因子：
2.9
通讯作者：
Quintero, Omar A.
中科院分区：
文献类型：
--
作者：
Adikes, Rebecca C.;Unrath, William C.;Yengo, Christopher M.;Quintero, Omar A.
线粒体动力学依赖于微管和肌动蛋白细胞骨架系统。在许多系统中都有关于肌球蛋白马达参与的证据，直到最近，脊椎动物中一种可能的线粒体运输马达才被描述出来。肌球蛋白 - XIX（MYO19）被预测为一种新型的肌球蛋白，先前已表明它能与线粒体结合，并且在异位表达时会增加线粒体网络动力学。我们对约40个MYO19直系同源物与约2000个其他肌球蛋白马达结构域序列进行的分析，确定了在第XIX类肌球蛋白中高度保守但在其他肌球蛋白类别中未发现的同源实例，这表明了MYO19特有的机械化学性质。对MYO19马达结构域的稳态生化分析表明，智人MYO19是一种有功能的马达。昆虫细胞表达的构建体以预测的化学计量比结合钙调蛋白作为轻链，并显示出肌动蛋白激活的ATP酶活性。在肌动蛋白共沉降实验中，MYO19构建体在ATP存在的情况下表现出对肌动蛋白的高亲和力，并且在滑动实验中使肌动蛋白丝发生移位。表达含有损害ATP酶活性突变的绿色荧光蛋白 - MYO19，不会像野生型MYO19那样增强线粒体网络动力学，这表明肌球蛋白马达活性是线粒体运动所必需的。所测得的MYO19的生化特性表明，它是一种高占空比马达，根据细胞微环境的不同，它可用于运输线粒体或锚定线粒体。
Mitochondrial dynamics are dependent on both the microtubule and actin cytoskeletal systems. Evidence for the involvement of myosin motors has been described in many systems, and until recently a candidate mitochondrial transport motor had not been described in vertebrates. Myosin-XIX (MYO19) was predicted to represent a novel class of myosin and had previously been shown to bind to mitochondria and increase mitochondrial network dynamics when ectopically expressed. Our analyses comparing ∼40 MYO19 orthologs to ∼2000 other myosin motor domain sequences identified instances of homology well-conserved within class XIX myosins that were not found in other myosin classes, suggesting MYO19-specific mechanochemistry. Steady-state biochemical analyses of the MYO19 motor domain indicate that Homo sapiens MYO19 is a functional motor. Insect cell-expressed constructs bound calmodulin as a light chain at the predicted stoichiometry and displayed actin-activated ATPase activity. MYO19 constructs demonstrated high actin affinity in the presence of ATP in actin-cosedimentation assays, and translocated actin filaments in gliding assays. Expression of GFP-MYO19 containing a mutation impairing ATPase activity did not enhance mitochondrial network dynamics, as occurs with wild-type MYO19, indicating that myosin motor activity is required for mitochondrial motility. The measured biochemical properties of MYO19 suggest it is a high-duty ratio motor that could serve to transport mitochondria or anchor mitochondria, depending upon the cellular microenvironment.
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影响因子：
9.2
作者：
De Vos, KJ;Allan, VJ;Sheetz, MP
通讯作者：
Sheetz, MP
DOI：
10.1073/pnas.96.24.13726
发表时间：
1999-11-23
影响因子：
11.1
作者：
De La Cruz, EM;Wells, AL;Sweeney, HL
通讯作者：
Sweeney, HL
影响因子：
3.4
作者：
De la Cruz, EM;Sweeney, HL;Ostap, EM
通讯作者：
Ostap, EM
影响因子：
64.8
作者：
FINER, JT;SIMMONS, RM;SPUDICH, JA
通讯作者：
SPUDICH, JA
影响因子：
16.2
作者：
DuBoff B;Götz J;Feany MB
通讯作者：
Feany MB