Mutational analysis of a putative polyphosphoinositide binding site in phospholipase C‐β 2

FEBS Letters

Camps, Montserrat²  Gierschik, Peter¹  Paula Simões, A.²  Schnabel, Petra² 

[1] Department of Pharmacology and Toxicology, University of Ulm, 89069 Ulm, Germany;German Cancer Research Center, Heidelberg, Germany

关键词: Phospholipase C;    Polyphosphoinositide;    Signal transduction;    Mutagenesis;    Binding site;    E. coli;    IPTG;    isopropyl β-d-thiogalactopyranoside;    PLC;    phosphoinositide-specific phospholipase C;    PtdInsP 2;    phosphatidylinositol 4;    5-bisphosphate;   

DOI  :  10.1016/0014-5793(95)00464-K

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The phosphatidylinositol 4,5-bisphosphate (PtdInsP ₂)-regulated actin-binding protein gelsolin and most phosphoinositide-specific phospholipases C (PLCs) comprise a basic amino acid motif ((K/R)xxxKxK(K/R); x denotes any amino acid) which was previously suggested to represent a PtdInsP ₂-binding site commonly present in these proteins. We have challenged this hypothesis for PLCβ ₂ by replacing one or several residues of this motif (KILIKNKK; residues 457–464) and examining the functional consequences of these alterations. The results show that the integrity of the basic motif is important for PtdInsP ₂ hydrolysis by PLCβ ₂. Replacement of lysines 463 or 461 by arginine led to reduction or complete loss, respectively, of enzyme activity. The results provide further support to the concept that the function of the basic motif within the various PLCs is to bind the enzyme substrate PtdInsP ₂.

【 授权许可】

Unknown