MYOSIN II STRUCTURE AND FUNCTION IN YEAST

这个项目的长期目标是了解类型的功能 II肌球蛋白是受调控的。细胞骨架肌球蛋白的整个超家族 根据它们的马达之间的序列相似性进行了分类 域名(Cheney等人，1993)。五个细胞骨架肌球蛋白已经被 在酿酒酵母中鉴定。有三个代表性的班级 到目前为止。尽管在高尔基体后囊泡运输中起着至关重要的作用 已经证明了酵母V型肌球蛋白Myo2p(Johnston等人，1991， Govindan等人，1995)，其他酵母肌球蛋白的功能，如 I型肌球蛋白，Myo3p和Myo5p(Goodson等人，1994)，以及第二种类型 V-myosin、Myo4p(Lillie和Brown，1994)尚不清楚。酵母菌II型 肌球蛋白，Myo1p似乎对细胞质分裂很重要(Watts等人，1987)。 有证据表明肌球蛋白功能之间存在冗余，这可能解释了 大多数肌球蛋白基因敲除突变的非致命性。A最近 已发现的激动素样电机蛋白Smy1p被证明是 肌球蛋白Myo1p和My02p的功能冗余，这表明 存在具有类似功能的其他类别的马达蛋白(布朗 每一位。以及Lillie和Brown，1994)。为了实现我们的长期目标 学期目标，有必要确定Myo1p的冗余基因产物。 识别这些基因将允许适当的发育 在体内表达和应用功能测试的缺失菌株 突变的重组MY01基因。这些研究还将扩大我们的 了解II型肌球蛋白与其他蛋白相互作用的类型 细胞蛋白质。 这项提议的具体目标是：1)进行基因筛查 为了鉴定myo1的合成致死突变(sl‘s)以便鉴定， 对编码功能蛋白的基因进行表征和突变 通过Myo1p实现冗余。2)作为AIM#1的长期延伸，多副本 将寻找my01合成致死表型(my01，s1)的抑制子。 以确定可以挽救合成致死表型的基因产品。 这种方法已经成功地用于另一种马达蛋白基因 Lillie and Brown(1994)。3)我们将探索可能的关联 Myo1p与几丁质酶的正常细胞定位和功能 (Cts1p)以测试在my01突变体中观察到的细胞质分裂延迟 反映了Myo1p在细胞内成分运输中的作用 在细胞分裂过程中细胞壁代谢所必需的。4)培训 通过研究获得生物医学研究生学位的学生 科学。

The long term goal of this project to understand how the functions of type II myosin are regulated. The entire superfamily of cytoskeletal myosins have been classified based on sequence similarities among their motor domains (Cheney et al.,, 1993). Five cytoskeletal myosins have been identified in Saccharomyces cerevisiae. with three representative classes to date. Although an essential role in post-Golgi vesicle transport has been demonstrated for a yeast type V myosin, Myo2p (Johnston et al., 1991, Govindan et al., 1995), the functions of other yeast myosins such as the type I myosins, Myo3p and Myo5p (Goodson et al., 1994), and a second type V myosin, Myo4p (Lillie and Brown, 1994) are not clear. The yeast type II myosin, Myo1p appears to be important for cytokinesis (Watts et al., 1987). There is evidence for redundancy among myosin functions which may explain th non-lethality of most myosin gene knockout mutations. A recently identified kinesin-like motor protein, Smy1p, has been shown to be functionally redundant with both myosins Myo1p and My02p which suggests that other classes of motor proteins with similar functions exist (Brown pers. comm., and Lillie and Brown, 1994 respectively). To achieve our long term goal, it is necessary to identify gene products redundant with Myo1p. Identification of these genes will allow the development appropriate deletion strains in which to express and apply functional tests in vivo for mutated recombinant MY01 genes. These studies will also expand our understanding of the type of interactions between type II myosins and other cellular proteins. The specific aims of this proposal are: 1) To carry out a genetic screen to identify synthetic lethal mutations (sl's) of myo1 in order to identify, characterize and mutate the genes encoding protein which are functionally redundant with Myo1p. 2) As a long term extension of aim #1, multi-copy suppressors of the my01 synthetic lethal phenotype (my01,sl) will be sought to identify gene products that can rescue the synthetic lethal phenotypes. This approach has been used successfully for another motor protein gene by lillie and Brown (1994). 3) We will explore the possible correlation between Myo1p and normal cellular localization and function of chitinase (Cts1p) to test whether the delay in cytokinesis observed in my01 mutants reflects a role for Myo1p in the intracellular transport of components required for cell wall metabolism during cell division. 4) To train students in research leading to graduate degrees in the biomedical sciences.