Specific binding sites for human luteinizing hormone in Neurospora crassa and Saccharomyces cerevisiae

T. A. Bramley, G. S. Menzies, R. J. Williams, O. S. Kinsman, D. J. Adams

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Specific binding sites for 125I-labelled human luteinizing hormone (hLH) were detected in microsomal and cytosolic fractions from Saccharomyces cerevisiae, Neurospora crassa and a wall-less (‘slime’) mutant of N. crassa. Scatchard analysis of hLH-binding to microscomes revealed the presence of both high affinity (Ka of 60–70 × 1010m−1) and lower affinity (Ka of 1·3–1·9 × 1010m−1) binding sites in each organism. 125I-hLH binding to both S. cerevisiae and N. crassa (wild type) microsomes was inhibited by low concentrations of Ca2+ and Mg2+ (30 μm), and by higher concentrations of Na+ and K+ (40 mm). Binding was also inhibited, in dose-dependent fashion, by partially-purified preparations of hLH and hCG. In contrast, highly purified hCG preparations were much less potent, though they strongly inhibited hLH binding to sheep corpus luteum LH-receptors. Moreover, high-purified hCG β-core protein inhibited hLH binding to S. cerevisiae and N. crassa microsomes in a dose-dependent manner, but had no effect on hLH binding to sheep luteal receptors. The properties of the S. cerevisiae and N. crassa LH-binding sites are similar to those of binders detected previously in Candida albicans. Thus, interactions between hLH-like molecules and their receptors may have a widespread distribution in the Ascomycotina and Deuteromycotina.

Original languageEnglish
Pages (from-to)1229-1234
Number of pages6
JournalMycological Research
Issue number11
Publication statusPublished - 1994

ASJC Scopus subject areas

  • Biotechnology
  • Ecology, Evolution, Behavior and Systematics
  • Genetics
  • Plant Science

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