title: KIT variants in bovine ovarian cells and corpus luteum.
abstract: We report the presence of KIT variants in granulosa and thecal cells of the follicle and endothelial and steroidogenic cells of the corpus luteum. Transcripts of both full-length splice variants, KIT and KITA, were ubiquitously detected in all cell types, in contrast to transcripts for truncated KIT. RT-PCR with exon-intron-specific primers suggested that KIT transcripts retained intron sequences. We used domain-specific KIT antibodies to identify truncated KIT proteins in cell conditioned media and lysates. These proteins represented soluble KIT and a so far disregarded intracellular KIT fragment, and were ubiquitously present. In contrast, glycosylated variants of full-length KIT were predominantly detected in thecal and endothelial cells. All KIT variants were encountered again in COS-7 cells transfected with a vector containing KITA. Phorbol 12-myristate-13-acetate treatment induced levels of truncated KITs, and this effect was repressed by the metalloproteinase inhibitor TAPI-1. Our findings show that ectodomain cleavage of full-length KIT generates an intracellular KIT. Our experiments suggest that replenishing full-length KIT differs among various ovarian cell types.
authors.affiliation: Institute of Anatomy, University of Leipzig, Leipzig, Germany.
authors.forename: Daniela
authors.initials: D
authors.lastname: Koch
authors.forename: Michiharu
authors.initials: M
authors.lastname: Sakurai
authors.forename: Katja
authors.initials: K
authors.lastname: Hummitzsch
authors.forename: Thomas
authors.initials: T
authors.lastname: Hermsdorf
authors.forename: Sabine
authors.initials: S
authors.lastname: Erdmann
authors.forename: Steffen
authors.initials: S
authors.lastname: Schwalbe
authors.forename: Jens-Uwe
authors.initials: JU
authors.lastname: Stolzenburg
authors.forename: Katharina
authors.initials: K
authors.lastname: Spanel-Borowski
authors.forename: Albert M
authors.initials: AM
authors.lastname: Ricken
mesh_terms: D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D019556:COS Cells; D002417:Cattle; D002478:Cells, Cultured; D002522:Chlorocebus aethiops; D003338:Corpus Luteum / Q000166:cytology / Q000378:metabolism*; D017931:DNA Primers / Q000235:genetics; D005260:Female; D015571:Follicular Fluid / Q000378:metabolism; D014644:Genetic Variation; D006031:Glycosylation; D006107:Granulosa Cells / Q000378:metabolism; D007438:Introns; D010053:Ovary / Q000166:cytology / Q000378:metabolism*; D010446:Peptide Fragments / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D019009:Proto-Oncogene Proteins c-kit / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D012995:Solubility; D013799:Theca Cells / Q000378:metabolism; D014162:Transfection
chemical_list: D017931:DNA Primers; D010446:Peptide Fragments; D012333:RNA, Messenger; D019009:Proto-Oncogene Proteins c-kit