Cloning and characterization of granulosa cell high-mobility group (HMG)-box protein-1, a novel HMG-box transcriptional regulator strongly expressed in rat ovarian granulosa cells.
Specific events in the ovary are dependent on gene expression in the tissue. By screening a rat ovarian granulosa cell cDNA library, a cDNA clone encoding a novel transcription factor-like protein containing a high-mobility group-box, referred to as granulosa cell high-mobility group-box protein-1 (GCX-1), was identified. The expression of GCX-1 is restricted to the hypothalamus, pituitary, testis, uterus, and ovary but was not detected in the adrenal gland. An in situ hybridization study revealed that the expression of GCX-1 was restricted to granulosa cell layers in early-stage follicles, and the expression was very low in large antral follicles and the corpus luteum, but localized expression in the testis or pituitary was not clear. Endogenous GCX-1 protein in the granulosa cells was identified by a Western blot analysis, and an analysis using the green fluorescence protein-GCX-1 fusion protein revealed that the GCX-1 protein was localized in the cell nucleus. GAL4 fusion protein-based assays demonstrated that GCX-1 is a potent transcriptional activator, and its putative transactivation domain was mapped to the region between amino acid residues 25 and 63 from the N terminus. These data strongly suggest that GCX-1 is likely a novel transcriptional activator that is exclusively expressed in reproductive tissues involving the hypothalamo-pituitary-gonadal axis, and functions as a specific regulator of follicular development, and may also participate in other specific events related to reproduction, particularly in the female.
Kajitani
Takashi
T
Department of Biochemistry, Fukui Medical University, Matsuoka, Fukui, 910-1193, Japan.
Mizutani
Tetsuya
T
Yamada
Kazuya
K
Yazawa
Takashi
T
Sekiguchi
Toshio
T
Yoshino
Miki
M
Kawata
Hiroko
H
Miyamoto
Kaoru
K
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D002467:Cell Nucleus / Q000737:chemistry; D002478:Cells, Cultured; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins; D005260:Female; D015870:Gene Expression; D015723:Gene Library; D006107:Granulosa Cells / Q000737:chemistry*; D049452:Green Fluorescent Proteins; D017403:In Situ Hybridization; D008164:Luminescent Proteins / Q000235:genetics; D008297:Male; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D010053:Ovary / Q000737:chemistry; D010902:Pituitary Gland / Q000737:chemistry; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017208:Rats, Wistar; D011993:Recombinant Fusion Proteins; D020133:Reverse Transcriptase Polymerase Chain Reaction; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics; D013737:Testis / Q000737:chemistry; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D014158:Transcription, Genetic; D020798:Two-Hybrid System Techniques
D004268:DNA-Binding Proteins; C052130:GAL4 protein, S cerevisiae; D008164:Luminescent Proteins; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; C484903:granulosa cell high-mobility group-box protein-1, rat; D049452:Green Fluorescent Proteins