Involvement of phosphatidylserine externalization in the down-regulation of c-myb expression in differentiating C2C12 cells.
Analysis of c-myb gene down-regulation in differentiating C212 cells revealed that in proliferating cells, c-myb expression is high and ceases as the proliferation rate decreases. However, a low level of c-myb mRNA was detected in confluent non-proliferating differentiating cells for an extended period of time before it declined to an undetectable level. The time course of c-myb gene silencing in differentiating cells correlated with exposition of phosphatidylserine (PS) on the cell surface. Moreover, the interaction of exposed PS with exogenously added annexin V perturbed PS-mediated cell signaling and transiently up-regulated the declining c-myb expression. We, therefore, suggest that cell surface-exposed PS, which plays a role in the process of myotube formation, is also involved in the down-regulation of c-myb expression.
Kaspar
Petr
P
Institute of Molecular Genetics, AS CR v.v.i., Vídenská 1083, Prague 4, CZ-14220, Czech Republic. kaspar@img.cas.cz
Dvorák
Michal
M
D000818:Animals; D017304:Annexin A5 / Q000378:metabolism; D001483:Base Sequence; D002454:Cell Differentiation; D002460:Cell Line; D017931:DNA Primers; D005455:Fluorescent Antibody Technique; D051379:Mice; D010718:Phosphatidylserines / Q000378:metabolism*; D020598:Proto-Oncogene Proteins c-myb / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction
D017304:Annexin A5; D017931:DNA Primers; D010718:Phosphatidylserines; D020598:Proto-Oncogene Proteins c-myb; D012333:RNA, Messenger