Two distinct regions in a yeast myosin-V tail domain are required for the movement of different cargoes.
Two distinct regions in a yeast myosin-V tail domain are required for the movement of different cargoes.
复制标题
酵母肌球蛋白-V尾部域中的两个不同区域是不同货物的移动所必需的。
DOI：
10.1083/jcb.150.3.513
复制
发表时间：
2000-08-07
影响因子：
7.8
通讯作者：
Weisman, L S
中科院分区：
文献类型：
--
作者：
Catlett, N L;Duex, J E;Tang, F;Weisman, L S
酿酒酵母肌球蛋白V（Myo 2 p）对于极化生长至关重要，最有可能通过将分泌囊泡运输到发育的芽中。Myo 2 p也是液泡运动所必需的，这是一个对生长不重要的过程。提出肌球蛋白-V COOH末端尾部结构域的球状区域结合货物。通过随机诱变这个球状尾巴，我们分离出六个新的单点突变体缺陷的液泡遗传，但不极化的增长。这些点突变聚集在11个氨基酸跨度中的4个氨基酸，表明该区域对液泡运动很重要。此外，通过对myo 2-Δ Afl II（缺失1，459 - 1，491位氨基酸）的表征，我们确定了极化生长所需的球状尾的第二个区域。而这种突变体不支持生长，它补充了myo 2 -2（G1248 D）细胞中的空泡遗传缺陷。此外，myo 2-Δ Afl II球状尾的过表达干扰液泡运动，但不干扰极化生长。这些数据表明，这第二个区域是空泡运动。这些不同的子域中的货物结合域的鉴定表明肌球蛋白-V可以移动多种货物。此外，这些研究表明，Myo 2 p的液泡受体不同于必需货物的受体。
The Saccharomyces cerevisiae myosin-V, Myo2p, is essential for polarized growth, most likely through transport of secretory vesicles to the developing bud. Myo2p is also required for vacuole movement, a process not essential for growth. The globular region of the myosin-V COOH-terminal tail domain is proposed to bind cargo. Through random mutagenesis of this globular tail, we isolated six new single point mutants defective in vacuole inheritance, but not polarized growth. These point mutations cluster to four amino acids in an 11-amino acid span, suggesting that this region is important for vacuole movement. In addition, through characterization of myo2-ΔAflII, a deletion of amino acids 1,459–1,491, we identified a second region of the globular tail specifically required for polarized growth. Whereas this mutant does not support growth, it complements the vacuole inheritance defect in myo2-2 (G1248D) cells. Moreover, overexpression of the myo2-ΔAflII globular tail interferes with vacuole movement, but not polarized growth. These data indicate that this second region is dispensable for vacuole movement. The identification of these distinct subdomains in the cargo-binding domain suggests how myosin-Vs can move multiple cargoes. Moreover, these studies suggest that the vacuole receptor for Myo2p differs from the receptor for the essential cargo.