RRC ID 48559
著者 Fukuda M, Kanno E, Ogata Y, Mikoshiba K.
タイトル Mechanism of the SDS-resistant synaptotagmin clustering mediated by the cysteine cluster at the interface between the transmembrane and spacer domains.
ジャーナル J Biol Chem
Abstract Synaptotagmin I (Syt I), a proposed major Ca(2+) sensor in the central nervous system, has been hypothesized as functioning in an oligomerized state during neurotransmitter release. We previously showed that Syts I, II, VII, and VIII form a stable SDS-resistant, beta-mercaptoethanol-insensitive, and Ca(2+)-independent oligomer surrounding the transmembrane domain (Fukuda, M., and Mikoshiba, K. (2000) J. Biol. Chem. 275, 28180-28185), but little is known about the molecular mechanism of the Ca(2+)-independent oligomerization by the synaptotagmin family. In this study, we analyzed the Ca(2+)-independent oligomerization properties of Syt I and found that it shows two distinct forms of self-oligomerization activity: stable SDS-resistant self-oligomerization activity and relatively unstable SDS-sensitive self-oligomerization activity. The former was found to be mediated by a post-translationally modified (i.e. fatty-acylated) cysteine (Cys) cluster (Cys-74, Cys-75, Cys-77, Cys-79, and Cys-82) at the interface between the transmembrane and spacer domains of Syt I. We also show that the number of Cys residues at the interface between the transmembrane and spacer domains determines the SDS- resistant oligomerizing capacity of each synaptotagmin isoform: Syt II, which contains seven Cys residues, showed the strongest SDS-resistant oligomerizing activity in the synaptotagmin family, whereas Syt XII, which has no Cys residues, did not form any SDS-resistant oligomers. The latter SDS-sensitive self-oligomerization of Syt I is mediated by the spacer domain, because deletion of the whole spacer domain, including the Cys cluster, abolished it, whereas a Syt I(CA) mutant carrying Cys to Ala substitutions still exhibited self-oligomerization. Based on these results, we propose that the oligomerization of the synaptotagmin family is regulated by two distinct mechanisms: the stable SDS-resistant oligomerization is mediated by the modified Cys cluster, whereas the relatively unstable (SDS-sensitive) oligomerization is mediated by the environment of the spacer domain.
巻・号 276(43)
ページ 40319-25
公開日 2001-10-26
DOI 10.1074/jbc.M105356200
PII S0021-9258(20)60114-4
PMID 11514560
MeSH Amino Acid Sequence Animals Calcium-Binding Proteins / metabolism* Cysteine* Membrane Glycoproteins / metabolism* Mice Molecular Sequence Data Nerve Tissue Proteins / metabolism* Protein Structure, Quaternary Receptor Aggregation / drug effects Receptors, Cell Surface / metabolism* Signal Transduction Sodium Dodecyl Sulfate / pharmacology Synaptotagmin I Synaptotagmins
IF 4.238
引用数 60
WOS 分野 BIOCHEMISTRY & MOLECULAR BIOLOGY
リソース情報
遺伝子材料 pEF-T7-Syt XII/Srg1 (Syt12) (RDB14692)