Involvement of the chicken liver 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase sequence His(444)-Arg-Glu-Arg in modulation of the bisphosphatase activity by its kinase domain

	Involvement of the chicken liver 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase sequence His(444)-Arg-Glu-Arg in modulation of the bisphosphatase activity by its kinase domain
	Zhu, Z; Ling, S; Yang, QH; Li, L
刊名	BIOCHEMICAL JOURNAL
	2001
卷号	357 期号:1 页码:513-520
关键词	bifunctional enzyme mutagenesis phosphorylation terminal region
通讯作者	Li, L (reprint author), Chinese Acad Sci, Shanghai Inst Biol Sci, Inst Biochem & Cell Biol, State Key Lab Mol Biol, Shanghai 200031, Peoples R China.,
英文摘要	The bisphosphatase activity of the hepatic bifunctional enzyme 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase is repressed by its kinase domain, and regulated by cAMP-dependent protein kinase (PKA)-catalysed phosphorylation. In the present study, the mechanism by which the bisphosphatase activity is repressed by the kinase domain and regulated by phosphorylation was investigated. We found that truncation of the C-terminus of the enzyme by 25, but not 20, amino acids dramatically enhanced the catalytic rate of the bisphosphatase, abrogated the inhibition by the kinase domain, and eliminated the effect of PKA-mediated phosphorylation on activity. In addition, mutation of His(444)-Arg-Glu-Arg to Ala-Ala-Glu-Ala had similar effects as the deletion. Moreover, the mutations also significantly affected the phosphorylation-mediated regulation of the kinase activity of the enzyme. Furthermore, the mutations altered the pH-dependence of the bisphosphatase, and the mutant bisphosphatases were more sensitive to modification by diethyl pyrocarbonate and guanidine-induced inactivation than the wildtype enzyme. Taken together, these results demonstrate that the sequence His(444)-Arg-Glu-Arg plays a critical role in repression of the bisphosphatase activity by both the N-terminal kinase domain and the C-terminal tail itself. These results also explain the activation of the bisphosphatase activity by PKA-catalysed phosphorylation, by suggesting that phosphorylation may relieve the inhibitory effect of the kinase domain that is mediated by the three basic residues in this sequence.
学科主题	Biochemistry & Molecular Biology
类目[WOS]	Biochemistry & Molecular Biology
关键词[WOS]	RAT 6-PHOSPHOFRUCTO-2-KINASE FRUCTOSE-2,6-BISPHOSPHATASE ; AMINO-ACID-SEQUENCE ; BIFUNCTIONAL ENZYME ; MOLECULAR-CLONING ; CRYSTAL-STRUCTURE ; ESCHERICHIA-COLI ; PHOSPHORYLATION ; EXPRESSION ; FRUCTOSE-6-PHOSPHATE ; SITE
收录类别	SCI
语种	英语
WOS记录号	WOS:000170112500021
内容类型	期刊论文
版本	出版稿
源URL	[http://202.127.25.143/handle/331003/2733]
专题	上海生化细胞研究所_上海生科院生化细胞研究所
推荐引用方式 GB/T 7714	Zhu, Z,Ling, S,Yang, QH,et al. Involvement of the chicken liver 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase sequence His(444)-Arg-Glu-Arg in modulation of the bisphosphatase activity by its kinase domain[J]. BIOCHEMICAL JOURNAL,2001,357(1):513-520.
APA	Zhu, Z,Ling, S,Yang, QH,&Li, L.(2001).Involvement of the chicken liver 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase sequence His(444)-Arg-Glu-Arg in modulation of the bisphosphatase activity by its kinase domain.BIOCHEMICAL JOURNAL,357(1),513-520.
MLA	Zhu, Z,et al."Involvement of the chicken liver 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase sequence His(444)-Arg-Glu-Arg in modulation of the bisphosphatase activity by its kinase domain".BIOCHEMICAL JOURNAL 357.1(2001):513-520.