Site-Directed Mutations at Phosphorylation Sites in Zea mays PHO1 Reveal Modulation of Enzymatic Activity by Phosphorylation at S566 in the L80 Region

被引：1

作者：

Shoaib, Noman ^{[1
,2
,3
,4
]}

Mughal, Nishbah ^{[1
]}

Liu, Lun ^{[1
,2
]}

Raza, Ali ^{[3
,4
]}

Shen, Leiyang ^{[1
,2
]}

Yu, Guowu ^{[1
,2
]}

机构：

[1] Sichuan Agr Univ, State Key Lab Crop Gene Explorat & Utilizat South, Chengdu 611130, Peoples R China

[2] Sichuan Agr Univ, Coll Agron, Natl Demonstrat Ctr Expt Crop Sci Educ, Chengdu 611130, Peoples R China

[3] Chinese Acad Sci, CAS Key Lab Mt Ecol Restorat Bioresource Utilizat, Biodivers Conservat Key Lab Sichuan Prov, Chengdu Inst Biol, Chengdu 610041, Peoples R China

[4] Univ Chinese Acad Sci, Beijing 101408, Peoples R China

来源：

PLANTS-BASEL | 2023年 / 12卷 / 18期

关键词：

activity; subcellular localization; plastidial starch phosphorylase; phosphorylation; PROTEIN-PROTEIN INTERACTIONS; ALPHA-GLUCAN PHOSPHORYLASE; PLASTIDIAL STARCH PHOSPHORYLASE; RICE ENDOSPERM; FUNCTIONAL INTERACTIONS; GLYCOGEN-PHOSPHORYLASE; BIOSYNTHETIC-ENZYMES; BRANCHING ENZYMES; MAIZE; METABOLISM;

D O I：

10.3390/plants12183205

中图分类号：

Q94 [植物学];

学科分类号：

071001 ;

摘要：

Starch phosphorylase (PHO) is a pivotal enzyme within the GT35-glycogen-phosphorylase (GT; glycosyltransferases) superfamily. Despite the ongoing debate surrounding the precise role of PHO1, evidence points to its substantial influence on starch biosynthesis, supported by its gene expression profile and subcellular localization. Key to PHO1 function is the enzymatic regulation via phosphorylation; a myriad of such modification sites has been unveiled in model crops. However, the functional implications of these sites remain to be elucidated. In this study, we utilized site-directed mutagenesis on the phosphorylation sites of Zea mays PHO1, replacing serine residues with alanine, glutamic acid, and aspartic acid, to discern the effects of phosphorylation. Our findings indicate that phosphorylation exerts no impact on the stability or localization of PHO1. Nonetheless, our enzymatic assays unveiled a crucial role for phosphorylation at the S566 residue within the L80 region of the PHO1 structure, suggesting a potential modulation or enhancement of PHO1 activity. These data advance our understanding of starch biosynthesis regulation and present potential targets for crop yield optimization.

引用

页数：16