Differential ubiquitin binding of the UBA domains from human c-Cbl and Cbl-b: NMR structural and biochemical insights

	Differential ubiquitin binding of the UBA domains from human c-Cbl and Cbl-b: NMR structural and biochemical insights
	Zhou, ZR; Gao, HC; Zhou, CJ; Chang, YG; Hong, J; Song, AX; Lin, DH; Hu, HY
刊名	PROTEIN SCIENCE
	2008
卷号	17 期号:10 页码:1805-1814
关键词	c-Cbl Cbl-b UBA ubiquitin binding NMR structure
通讯作者	Hu, HY (reprint author), Chinese Acad Sci, State Key Lab Mol Biol, Inst Biochem & Cell Biol, Shanghai Inst Biol Sci, Shanghai 200031, Peoples R China.,dhlin@mail.shcnc.ac.cn ; hyhu@sibs.ac.cn
英文摘要	The Cbl proteins, RING-type E3 ubiquitin ligases, are responsible for ubiquitinating the activated tyrosine kinases and targeting them for degradation. Both c-Cbl and Cbl-b have a UBA (ubiquitin-associated) domain at their C-terminal ends, and these two UBA domains share a high sequence similarity (75%). However, only the UBA from Cbl-b, but not from c-Cbl, can bind ubiquitin (Ub). To understand the mechanism by which the UBA domains specifically interact with Ub with different affinities, we determined the solution NMR structures of these two UBA domains, cUBA from human c-Cbl and UBAb from Cbl-b. Their structures show that these two UBA domains share the same fold, a compact three-helix bundle, highly resembling the typical UBA fold. Chemical shift perturbation experiments reveal that the helix-1 and loop-1 of UBAb form a predominately hydrophobic surface for Ub binding. By comparing the Ub-interacting surface on UBAb and its counterpart on cUBA, we find that the hydrophobic patch on cUBA is interrupted by a negatively charged residue Glu12. Fluorescence titration data show that the Ala12Glu mutant of UBAb completely loses the ability to bind Ub, whereas the mutation disrupting the dimerization has no significant effect on Ub binding. This study provides structural and biochemical insights into the Ub binding specificities of the Cbl UBA domains, in which the hydrophobic surface distribution on the first helix plays crucial roles in their differential affinities for Ub binding. That is, the amino acid residue diversity in the helix-1 region, but not the dimerization, determines the abilities of various UBA domains binding with Ub.
学科主题	Biochemistry & Molecular Biology
类目[WOS]	Biochemistry & Molecular Biology
关键词[WOS]	GROWTH-FACTOR RECEPTOR ; CHEMICAL-SHIFT ; TYROSINE PHOSPHORYLATION ; MEDIATED DIMERIZATION ; DOWN-REGULATION ; PROTEIN LIGASE ; V-CBL ; COMPLEX ; IDENTIFICATION ; PROTOONCOGENE
收录类别	SCI
语种	英语
WOS记录号	WOS:000259401900018
内容类型	期刊论文
版本	出版稿
源URL	[http://202.127.25.143/handle/331003/1448]
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	Zhou, ZR,Gao, HC,Zhou, CJ,et al. Differential ubiquitin binding of the UBA domains from human c-Cbl and Cbl-b: NMR structural and biochemical insights[J]. PROTEIN SCIENCE,2008,17(10):1805-1814.
APA	Zhou, ZR.,Gao, HC.,Zhou, CJ.,Chang, YG.,Hong, J.,...&Hu, HY.(2008).Differential ubiquitin binding of the UBA domains from human c-Cbl and Cbl-b: NMR structural and biochemical insights.PROTEIN SCIENCE,17(10),1805-1814.
MLA	Zhou, ZR,et al."Differential ubiquitin binding of the UBA domains from human c-Cbl and Cbl-b: NMR structural and biochemical insights".PROTEIN SCIENCE 17.10(2008):1805-1814.