KIT variants in bovine ovarian cells and corpus luteum

Growth Factors. 2009 Apr;27(2):100-13. doi: 10.1080/08977190802707571.

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.

MeSH terms

  • Alternative Splicing
  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • COS Cells
  • Cattle
  • Cells, Cultured
  • Chlorocebus aethiops
  • Corpus Luteum / cytology
  • Corpus Luteum / metabolism*
  • DNA Primers / genetics
  • Female
  • Follicular Fluid / metabolism
  • Genetic Variation
  • Glycosylation
  • Granulosa Cells / metabolism
  • Introns
  • Ovary / cytology
  • Ovary / metabolism*
  • Peptide Fragments / chemistry
  • Peptide Fragments / genetics
  • Peptide Fragments / metabolism
  • Protein Processing, Post-Translational
  • Proto-Oncogene Proteins c-kit / chemistry
  • Proto-Oncogene Proteins c-kit / genetics*
  • Proto-Oncogene Proteins c-kit / metabolism
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Sequence Homology, Amino Acid
  • Sequence Homology, Nucleic Acid
  • Solubility
  • Theca Cells / metabolism
  • Transfection

Substances

  • DNA Primers
  • Peptide Fragments
  • RNA, Messenger
  • Proto-Oncogene Proteins c-kit