UNCOATING PROTEIN (HSC70) BINDS A CONFORMATIONALLY LABILE DOMAIN OF CLATHRIN LIGHT CHAIN LCA TO STIMULATE ATP HYDROLYSIS
UNCOATING PROTEIN (HSC70) BINDS A CONFORMATIONALLY LABILE DOMAIN OF CLATHRIN LIGHT CHAIN LCA TO STIMULATE ATP HYDROLYSIS
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DOI：
10.1016/0092-8674(90)90263-e
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发表时间：
1990-09-07
期刊：
影响因子：
64.5
通讯作者：
HILL, BL
中科院分区：
文献类型：
--
作者：
DELUCAFLAHERTY, C;MCKAY, DB;HILL, BL
网格蛋白包被的囊泡的去包被由热休克同源蛋白hsc 70介导，并且需要网格蛋白轻链（LCa和LCb）和ATP水解。我们证明，纯化的轻链和合成肽从它们的序列结合hsc 70刺激ATP水解。LCa比LCb更有效地刺激hsc 70 ATP酶和抑制hsc 70的网格蛋白脱壳。这些差异与形成hsc 70结合位点的富含脯氨酸和甘氨酸的区域（残基47-71）的高序列差异相关。对于LCa，但不是LCb，该区域在离子强度或钙离子浓度扰动时经历可逆的构象变化。我们的研究结果表明，LCa是更重要的相互作用与hsc 70比LCb，并建议一个模型，其中LCa构象调节包被囊泡脱壳。
Uncoating of clathrin-coated vesicles is mediated by the heat shock cognate protein, hsc70, and requires clathrin light chains (LCa and LCb) and ATP hydrolysis. We demonstrate that purified light chains and synthetic peptides derived from their sequences bind hsc70 to stimulate ATP hydrolysis. LCa is more effective than LCb in stimulating hsc70 ATPase and in inhibiting clathrin uncoating by hsc70. These differences correlate with high sequence divergence in the proline- and glycine-rich region (residues 47-71) that forms the hsc70 binding site. For LCa, but not LCb, this region undergoes reversible conformational changes upon perturbation of the ionic strength or the calcium ion concentration. Our results show that LCa is more important for interactions with hsc70 than is LCb and suggest a model in which the LCa conformation regulates coated vesicle uncoating.