Identification and functional analysis of novel phosphorylation sites in Cx43 in rat primary granulosa cells.
The gap junctional intercellular communication mediated by Cx43 plays indispensable roles in both germ line development and postnatal folliculogenesis. In this study, we focused on the effect of follicle-stimulating hormone (FSH) on the Cx43 protein in rat primary granulosa cells and found that FSH stimulation elevated the phosphorylation in addition to the protein level of Cx43. Serine residues in the carboxyl-terminal region were exclusively phosphorylated in this system and we identified Ser365, Ser368, Ser369 and Ser373 as major phosphorylation sites by FSH stimulation. A Cx43 variant containing mutations at all these serine residues was found to severely reduce dye transfer activity when assayed in HeLa cells. The present study revealed a novel regulatory mechanism of Cx43-mediated gap junctional intercellular communication through phosphorylation in the carboxyl-terminus.
Yogo
Keiichiro
K
Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara 630-0101, Japan.
Ogawa
Takuya
T
Akiyama
Motofusa
M
Ishida
Norihiro
N
Takeya
Tatsuo
T
D000818:Animals; D001692:Biological Transport; D002478:Cells, Cultured; D004396:Coloring Agents / Q000378:metabolism; D018031:Connexin 43 / Q000737:chemistry* / Q000378:metabolism / Q000502:physiology*; D005260:Female; D005640:Follicle Stimulating Hormone / Q000494:pharmacology; D006107:Granulosa Cells / Q000187:drug effects / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D016297:Mutagenesis, Site-Directed; D010449:Peptide Mapping; D010455:Peptides / Q000737:chemistry; D010766:Phosphorylation; D010768:Phosphoserine / Q000032:analysis; D051381:Rats
D004396:Coloring Agents; D018031:Connexin 43; D010455:Peptides; D010768:Phosphoserine; D005640:Follicle Stimulating Hormone