title: Liprin-α is involved in exocytosis and cell spreading in mast cells.
abstract: The active zone is a specialized region of the presynaptic plasma membrane where the neurotransmitter release occurs by exocytosis. Mast cells also release inflammatory mediators by exocytosis resulting in induction of allergic responses. In our previous reports, we found that active zone proteins, Munc13-1 and ELKS regulates exocytosis of mast cell positively. In this study, we investigated the involvement of liprin-α, another active zone protein, in exocytosis in mast cells. We found that three isoforms of liprin-α, liprin-α1, -α2 and -α3 were expressed. Immunocytochemical experiments revealed that liprin-α1 resided both in the cytoplasm and on the plasma membrane. Upon stimulation with antigen, the area of a cell increased remarkably due to cell spreading and the distribution of liprin-α1 became punctuated. Interestingly, knockdown of liprin-α1 caused decrease in exocytotic release and cell spreading. These results suggest that liprin-α1 facilitates exocytosis and cell spreading, and these events might have correlated each other in mast cells.
authors.affiliation: Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1, Tanabe-dori, Mizuho-ku, Nagoya 467-8603, Japan.
authors.forename: Hidehiro
authors.initials: H
authors.lastname: Nomura
authors.forename: Satoshi
authors.initials: S
authors.lastname: Tadokoro
authors.forename: Naohide
authors.initials: N
authors.lastname: Hirashima
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D015550:Cell Degranulation / Q000235:genetics; D045744:Cell Line, Tumor; D005089:Exocytosis / Q000235:genetics; D005786:Gene Expression Regulation; D055785:Gene Knockdown Techniques; D042541:Intracellular Space / Q000378:metabolism; D008407:Mast Cells / Q000378:metabolism*; D021381:Protein Transport / Q000235:genetics; D051381:Rats
chemical_list: D048868:Adaptor Proteins, Signal Transducing; C561787:Ppfia1 protein, rat