@article{oai:kanazawa-u.repo.nii.ac.jp:00015371,
 author = {Osada, Yoichi and Sunatani, Toshiro and Kim, In-San and Nakanishi, Yoshinobu and Shiratsuchi, Akiko},
 issue = {3},
 journal = {Journal of biochemistry},
 month = {Mar},
 note = {Class B scavenger receptor type I (SR-BI) is a phosphatidylserine (PS)-recognizing receptor of testicular Sertoli cells responsible for the phagocytosis of spermatogenic cells undergoing apoptosis. Here, we determined signal mediators that compose a signalling pathway for SR-BI-induced phagocytosis. Results of a yeast two-hybrid analysis and a cell-free binding assay indicated that SR-BI binds to engulfment adapter protein (GULP) using the C-terminal intracellular domain. A co-immunoprecipitation analysis showed the existence of a complex of GULP and SR-BI in cells prior to the activation of SR-BI by PS. A reduction of GULP expression in phagocytes decreased the SR-BI-mediated phagocytosis of apoptotic cells. Administration to phagocytes of PS-containing liposomes increased the levels of the GTP-bound form of Rac1 and the phosphorylated forms of mitogen-activated protein kinases (MAPK) p38 and extracellular signal-related kinase 1 and 2. Finally, lowering the expression of GULP abrogated MAPK phosphorylation, and the presence of MAPK inhibitors reduced the level of GTP-bound Rac1 in PS-activated phagocytes. These results collectively suggested the following signalling pathway for the SR-BI-induced phagocytosis: (i) PS-recognizing SR-BI activates associated GULP; (ii) activated GULP induces MAPK phosphorylation; (iii) activated MAPK increases GTP-bound Rac1; and (iv) activated Rac1 induces a rearrangement of the actin cytoskeleton., 金沢大学医薬保健研究域薬学系},
 pages = {387--394},
 title = {Signalling pathway involving GULP, MAPK and Rac1 for SR-BI-induced phagocytosis of apoptotic cells.},
 volume = {145},
 year = {2009}
}