Architecture and activation of human muscle phosphorylase kinase.

Autor: Yang X; State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, P.R. China., Zhu M; State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, P.R. China., Lu X; Changping Laboratory, Beijing, P.R. China.; Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, P.R. China., Wang Y; State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, P.R. China., Xiao J; State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, P.R. China. junyuxiao@pku.edu.cn.; Changping Laboratory, Beijing, P.R. China. junyuxiao@pku.edu.cn.; Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, P.R. China. junyuxiao@pku.edu.cn.
Jazyk: angličtina
Zdroj: Nature communications [Nat Commun] 2024 Mar 28; Vol. 15 (1), pp. 2719. Date of Electronic Publication: 2024 Mar 28.
DOI: 10.1038/s41467-024-47049-2
Abstrakt: The study of phosphorylase kinase (PhK)-regulated glycogen metabolism has contributed to the fundamental understanding of protein phosphorylation; however, the molecular mechanism of PhK remains poorly understood. Here we present the high-resolution cryo-electron microscopy structures of human muscle PhK. The 1.3-megadalton PhK α 4 β 4 γ 4 δ 4 hexadecamer consists of a tetramer of tetramer, wherein four αβγδ modules are connected by the central β 4 scaffold. The α- and β-subunits possess glucoamylase-like domains, but exhibit no detectable enzyme activities. The α-subunit serves as a bridge between the β-subunit and the γδ subcomplex, and facilitates the γ-subunit to adopt an autoinhibited state. Ca 2+ -free calmodulin (δ-subunit) binds to the γ-subunit in a compact conformation. Upon binding of Ca 2+ , a conformational change occurs, allowing for the de-inhibition of the γ-subunit through a spring-loaded mechanism. We also reveal an ADP-binding pocket in the β-subunit, which plays a role in allosterically enhancing PhK activity. These results provide molecular insights of this important kinase complex.
(© 2024. The Author(s).)
Databáze: MEDLINE
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