Engagement of CD99 triggers the exocytic transport of ganglioside GM1 and the reorganization of actin cytoskeleton.
We studied the role of lipid rafts and actin cytoskeleton in CD99-mediated signaling to elucidate the mechanism of protein transport upon CD99 engagement. CD99 engagement in Jurkat cells elicited the exocytic transport of GM1 as well as several surface molecules closely related with CD99 functions. In addition, CD99 molecules were rapidly incorporated into lipid rafts and appeared to rearrange the actin cytoskeleton upon CD99 stimulation. Association of CD99 with actin cytoskeleton was inhibited by methyl-beta-cyclodextrin, while CD99-mediated GM1 clustering was inhibited by cytochalasin D. Therefore, we suggest that CD99 may play a role in the vesicular transport of transmembrane proteins and lipid rafts from the intracellular location to the cell surface, possibly by effecting actin cytoskeleton reorganization.
Yoon
Sang Soon
SS
Department of Pathology and Center for Molecular Medicine, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Suwon, South Korea.
Jung
Kyung In
KI
Choi
Yoon-La
YL
Choi
Eun Young
EY
Lee
Im-Soon
IS
Park
Seong Hoe
SH
Kim
Tae Jin
TJ
D000071443:12E7 Antigen; D000199:Actins / Q000378:metabolism*; D015703:Antigens, CD / Q000378:metabolism*; D001692:Biological Transport; D015815:Cell Adhesion Molecules / Q000378:metabolism*; D003599:Cytoskeleton / Q000378:metabolism*; D005089:Exocytosis; D005677:G(M1) Ganglioside / Q000378:metabolism*; D006801:Humans; D019169:Jurkat Cells
D000071443:12E7 Antigen; D000199:Actins; D015703:Antigens, CD; C061828:CD99 protein, human; D015815:Cell Adhesion Molecules; D005677:G(M1) Ganglioside