論文 - 詳細
RRC ID | 48870 |
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著者 | Kojima T, Fukuda M, Aruga J, Mikoshiba K. |
タイトル | Calcium-dependent phospholipid binding to the C2A domain of a ubiquitous form of double C2 protein (Doc2 beta). |
ジャーナル | J Biochem |
Abstract |
Rabphilin 3A and Doc2 alpha are synaptic vesicle-associated proteins, and are thought to function as Ca2+ sensors in neurotransmitter release. If either rabphilin 3A or Doc2 alpha plays a role in membrane trafficking, like the synaptotagmins, then non-neural forms should be present. Here we describe the isolation of a mouse cDNA which encodes a novel Doc2 homologue (Doc2 beta) that is present in all tissues. The encoded protein, which is highly homologous to human Doc2 alpha (70% identity), is composed of 412 amino acids with a calculated relative molecular mass (M(r)) of 45,837. The sequence identity is especially high in two C2 domains (74% in C2A and 84% in C2B). Northern and Western blot analyses have shown that Doc2 beta is expressed in all cell lines and tissues tested. Ca(2+)-dependent phospholipid binding assaying of recombinant fusion proteins revealed that the single C2A domain, but not the C2B domain, of Doc2 beta binds phosphatidycholine and phosphatidylserine (2.5:1, w/w) liposomes. The binding is Ca(2+)-dependent, with an EC50 value of approximately 1 microM and a Hill coefficient of approximately 3, which are comparable to those of synaptotagmins, rabphilin 3A and Doc2 alpha. Our results suggest that Doc2 beta is involved in constitutive membrane trafficking. |
巻・号 | 120(3) |
ページ | 671-6 |
公開日 | 1996-9-1 |
DOI | 10.1093/oxfordjournals.jbchem.a021464 |
PMID | 8902635 |
MeSH | Adaptor Proteins, Signal Transducing Amino Acid Sequence Animals Base Sequence Binding Sites Calcium / pharmacology Calcium-Binding Proteins / biosynthesis Calcium-Binding Proteins / chemistry* Calcium-Binding Proteins / metabolism* Cerebellum / metabolism* Cloning, Molecular GTP-Binding Proteins / metabolism Humans Kinetics Liposomes Membrane Glycoproteins / metabolism Mice Mice, Inbred ICR Molecular Sequence Data Nerve Tissue Proteins / biosynthesis Nerve Tissue Proteins / chemistry* Nerve Tissue Proteins / metabolism* Phosphatidylcholines / metabolism Phosphatidylserines / metabolism Phospholipids / metabolism* Recombinant Fusion Proteins / biosynthesis Recombinant Fusion Proteins / chemistry Recombinant Fusion Proteins / metabolism Sequence Homology, Amino Acid Synaptotagmins Vesicular Transport Proteins rab GTP-Binding Proteins* |
IF | 2.476 |
引用数 | 43 |
WOS 分野 | BIOCHEMISTRY & MOLECULAR BIOLOGY |
リソース情報 | |
遺伝子材料 | pEF-T7-mouse Doc2 beta (RDB15101) |