title: Functional analysis of the extended N-terminal region in PLC-δ1 (MlPLC-δ1) from the mud loach, Misgurnus mizolepis.
abstract: Mud loach phospholipase C-δ1 (MlPLC-δ1) contains all the characteristic domains found in mammalian PLC-δ isozymes (pleckstrin homology domain, EF-hands, X–Y catalytic region, and C2 domain) as well as an extended 26-amino acid (aa)-long N-terminal region that is an alternative splice form of PLC-δ1 and is novel to vertebrate PLC-δ. In the present structure-function analysis, deletion of the extended N-terminal region caused complete loss of phosphatidylinositol (PI)- and phosphatidylinositol 4,5-bisphosphate (PIP2)-hydrolyzing activity in MlPLC-δ1. Additionally, recombinant full-length MlPLC-δ1 PLC activity was reduced in a dose-dependent manner by coincubation with the 26-aa protein fragment. Using a protein-lipid overlay assay, both full-length MlPLC-δ1 and the 26-aa protein fragment had substantial affinity for PIP2, whereas deletion of the 26-aa region from MlPLC-δ1 (MlPLC-δ1-deletion) resulted in lower affinity for PIP2. These results suggest that the novel N-terminal exon of MlPLC-δ1 could play an important role in the regulation of PLC-δ1.
authors.forename: Na Young
authors.initials: NY
authors.lastname: Kim
authors.forename: Sang Jung
authors.initials: SJ
authors.lastname: Ahn
authors.forename: Moo-Sang
authors.initials: MS
authors.lastname: Kim
authors.forename: Jung Soo
authors.initials: JS
authors.lastname: Seo
authors.forename: Se Hwan
authors.initials: SH
authors.lastname: Jung
authors.forename: Sung Hwan
authors.initials: SH
authors.lastname: Park
authors.forename: Hyung Ho
authors.initials: HH
authors.lastname: Lee
authors.forename: Joon Ki
authors.initials: JK
authors.lastname: Chung
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D003531:Cypriniformes / Q000378:metabolism*; D006868:Hydrolysis; D008969:Molecular Sequence Data; D019269:Phosphatidylinositol 4,5-Diphosphate / Q000378:metabolism; D054803:Phospholipase C delta / Q000737:chemistry* / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D017384:Sequence Deletion; D013379:Substrate Specificity
chemical_list: D019269:Phosphatidylinositol 4,5-Diphosphate; D011994:Recombinant Proteins; D054803:Phospholipase C delta