Decreased basal mucus secretion by Slp2-a-deficient gastric surface mucous cells.
Synaptotagmin-like protein (Slp) 2-a is a putative Rab27A/B-effector protein and is implicated in intracellular membrane transport. However, the precise tissue distribution of Slp2-a protein and its functions remain largely unknown. In this study we used a specific anti-Slp2-a antibody to investigate the tissue distribution of Slp2-a in mice and found that Slp2-a is most abundantly expressed in mouse stomach. Co-immunoprecipitation experiments indicated that Slp2-a interacts with Rab27A/B in vivo. We also discovered that Slp2-a and Rab27A/B are predominantly localized at the apical region of gastric-surface mucous cells, where mucus granules are accumulated. Analysis of Slp2-a mutant mice generated by homologous recombination showed a reduced number of mucus granules, a deficiency of granule docking with the apical plasma membrane in the gastric-surface mucous cells and reduction of mucus secretion by Slp2-a-deficient gastric primary cells. Based on these results, we propose that Slp2-a is part of the mucin secretory machinery in surface mucous cells of mouse stomach.
Saegusa
Chika
C
Fukuda Initiative Research Unit, RIKEN (The Institute of Physical and Chemical Research), 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
Tanaka
Toru
T
Tani
Satoru
S
Itohara
Shigeyoshi
S
Mikoshiba
Katsuhiko
K
Fukuda
Mitsunori
M
D000595:Amino Acid Sequence; D000818:Animals; D002462:Cell Membrane / Q000378:metabolism; D005753:Gastric Mucosa / Q000378:metabolism* / Q000473:pathology; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008817:Mice, Mutant Strains; D008969:Molecular Sequence Data; D009093:Mucus / Q000378:metabolism*; D011995:Recombination, Genetic; D013270:Stomach / Q000473:pathology; D020691:rab GTP-Binding Proteins / Q000378:metabolism; D000075745:rab27 GTP-Binding Proteins
D008565:Membrane Proteins; C424134:Sytl2 protein, mouse; D000075745:rab27 GTP-Binding Proteins; C512962:Rab27a protein, mouse; D020691:rab GTP-Binding Proteins