Expression of ectodermal neural cortex 1 and its association with actin during the ovulatory process in the rat.
Ectodermal neural cortex (ENC) 1, a member of the kelch family of genes, is an actin-binding protein and plays a pivotal role in neuronal and adipocyte differentiation. The present study was designed to examine the gonadotropin regulation and action of ENC1 during the ovulatory process in immature rats. The levels of ENC1 mRNA and protein were stimulated by LH/human chorionic gonadotropin (hCG) within 3 h both in vivo and in vitro. In situ hybridization analysis revealed that ENC1 mRNA was localized not only in theca/interstitial cells but also in granulosa cells of preovulatory follicles but not of growing follicles in pregnant mare's serum gonadotropin/hCG-treated ovaries. LH-induced ENC1 expression was suppressed by a high dose of protein kinase C inhibitor RO 31-8220 (10 microM) but not by low doses of RO 31-8220 (0.1-1.0 microM), suggesting the involvement of atypical protein kinase C. ENC1 was detected in both nucleus and cytoplasm that was increased by LH/hCG treatment. Both biochemical and morphological analysis revealed that LH/hCG treatment increased actin polymerization within 3 h in granulosa cells. Interestingly, ENC1 physically associated with actin and treatment with cytochalasin D, an actin-depolymerizing agent, abolished this association. Confocal microscopy further demonstrated the colocalization of ENC1 with filamentous actin (F-actin). The present study demonstrates that LH/hCG stimulates ENC1 expression and increases F-actin formation in granulosa cells. The present study further shows the physical association of ENC1 and F-actin, implicating the role of ENC1 in cytoskeletal reorganization during the differentiation of granulosa cells.
Kim
Sun-Gyun
SG
Hormone Research Center and School of Biological Sciences and Technology, Chonnam National University, Kwangju 500-712, Republic of Korea.
Jang
Soo-Jeong
SJ
Soh
Jaemog
J
Lee
Keesook
K
Park
Jin-Ki
JK
Chang
Won-Kyong
WK
Park
Eung-Woo
EW
Chun
Sang-Young
SY
D000199:Actins / Q000378:metabolism*; D000818:Animals; D015152:Blotting, Northern; D015153:Blotting, Western; D002478:Cells, Cultured; D006063:Chorionic Gonadotropin / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D005455:Fluorescent Antibody Technique; D006107:Granulosa Cells / Q000187:drug effects / Q000378:metabolism; D047468:Immunoprecipitation; D017403:In Situ Hybridization; D066298:In Vitro Techniques; D007211:Indoles / Q000494:pharmacology; D007986:Luteinizing Hormone / Q000494:pharmacology; D008840:Microfilament Proteins / Q000235:genetics / Q000378:metabolism*; D009479:Neuropeptides / Q000235:genetics / Q000378:metabolism*; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D010053:Ovary / Q000187:drug effects* / Q000378:metabolism*; D011485:Protein Binding; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012102:Reproductive Control Agents / Q000494:pharmacology
D000199:Actins; D006063:Chorionic Gonadotropin; D004791:Enzyme Inhibitors; D007211:Indoles; D008840:Microfilament Proteins; D009479:Neuropeptides; D009687:Nuclear Proteins; D012102:Reproductive Control Agents; C112302:ectodermal-neural cortex 1 protein; D007986:Luteinizing Hormone; D011493:Protein Kinase C; C064758:Ro 31-8220