Department of Chemistry and Biochemistry, University of North Florida, Jacksonville, FL, USA.
Department of Biochemistry, University of Wisconsin - Madison, WI, USA.
FEBS Lett. 2024 Jun;598(12):1465-1477. doi: 10.1002/1873-3468.14857. Epub 2024 Mar 26.
J-domain proteins are critical Hsp70 co-chaperones. A and B types have a poorly understood glycine-rich region (G) adjacent to their N-terminal J-domain (J). We analyzed the ability of J/G segments of yeast Class B Sis1 and a suppressor variant of Class A, Ydj1, to rescue the inviability of sis1-∆. In each, we identified a cluster of G residues required for rescue. Both contain conserved hydrophobic and acidic residues and are predicted to form helices. While, as expected, the Sis1 segment docks on its J-domain, that of Ydj1 does not. However, data suggest both interact with Hsp70. We speculate that the G-Hsp70 interaction of Classes A and B J-domain proteins can fine tune the activity of Hsp70, thus being particularly important for the function of Class B.
J 结构域蛋白是 HSP70 的关键共伴侣。A 型和 B 型蛋白的 N 端 J 结构域（J）附近有一个甘氨酸丰富的区域（G），但其功能尚未完全阐明。我们分析了酵母 B 类 Sis1 和 A 类 Ydj1 的 J/G 片段的功能，以拯救 sis1-∆的生存能力。在每种情况下，我们都鉴定出一组对拯救有重要作用的 G 残基。它们都含有保守的疏水性和酸性残基，预测可形成螺旋。虽然正如预期的那样，Sis1 片段与 J 结构域对接，但 Ydj1 片段没有。然而，数据表明两者都与 Hsp70 相互作用。我们推测 A 类和 B 类 J 结构域蛋白的 G-Hsp70 相互作用可以微调 Hsp70 的活性，因此对 B 类的功能尤为重要。
