Synaptotagmin-like protein 1-3: a novel family of C-terminal-type tandem C2 proteins.

Synaptotagmins (Syt), rabphilin-3A, and Doc2 belong to a family of carboxyl terminal type (C-type) tandem C2 proteins and are thought to be involved in vesicular trafficking. We have cloned and characterized a novel family of C-type tandem C2 proteins, designated Slp1-3 (synaptotagmin-like protein 1-3). The Slp1-3 C2 domains show high homology to granuphilin-a C2 domains, but the amino-terminal domain of Slp1-3 does not contain any known protein motifs or a transmembrane domain. A subcellular fractionation study indicated that Slp1-3 proteins are peripheral membrane proteins. Phospholipid binding experiments indicated that Slp3 is a Ca(2+)-dependent isoform, but Slp1 and Slp2 are Ca(2+)-independent isoforms, because only the Slp3 C2A domain showed Ca(2+)-dependent phospholipid binding activity. The C-terminus of Slp1-3 also bound neurexin Ialpha in vitro, in the same manner as Syt family proteins, which may be important for the membrane association of Slp1-3. In addition, Slp family proteins are differentially distributed in different mouse tissues and at different developmental stages.

Fukuda M ，Mikoshiba K 《BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS》

Novel splicing isoforms of synaptotagmin-like proteins 2 and 3: identification of the Slp homology domain.

Fukuda M ，Saegusa C ，Mikoshiba K 《-》

The C2A domain of synaptotagmin-like protein 3 (Slp3) is an atypical calcium-dependent phospholipid-binding machine: comparison with the C2A domain of synaptotagmin I.

Fukuda M 《-》

Mechanism of phospholipid binding by the C2A-domain of synaptotagmin I.

Zhang X ，Rizo J ，Südhof TC 《BIOCHEMISTRY》

The tricalbin C2 domains: lipid-binding properties of a novel, synaptotagmin-like yeast protein family.

Schulz TA ，Creutz CE 《BIOCHEMISTRY》