PubMed · 3444051
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
T Ohashi, H Ohmori. 1987. [Spermatogenesis].. https://pubmed.ncbi.nlm.nih.gov/3444051/
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
This paper reports, for the first time, the purification of a phospholipid transfer protein (PLTP) from a fungus, Neurospora crassa. The protein was purified from the post-microsomal supernatant of N. crassa by successive chromatography on DEAE-cellulose, Sephadex-G75 and PBE 94 (pH 4-7). The purified protein (M(r) 38,000) was found to transfer phosphatidylinositol preferentially over phosphatidylcholine, like the PLTP from the yeast, Saccharomyces cerevisiae. PC transfer was completely inhibited by inactivation of free amino groups or tryptophan residues. Surprisingly, the protein did not cross-react with antibodies against the bovine brain PITP. The cellular content of the protein was maximal during the logarithmic phase of growth. However, no direct correlation between the content of the protein and PC transfer activity could be demonstrated.
The testis of the salamander, Necturus maculosus, is advantageous for studying biochemical changes during spermatogenesis because germ cells and associated Sertoli and Leydig cells are topographically separated by stage of development. Using extracts of staged tissue samples and [3H]testosterone (T) in a standard binding assay, followed by Sephadex LH-20 or DNA-cellulose chromatography to separate free and bound steroid, we have identified a T-binding protein having physicochemical characteristics of a classical androgen receptor (AR): high affinity (Kd = 10(-9) M), limited capacity (Bmax) = 10(-10) M or 350 fmol/g tissue) and androgen specificity (T = 5 alpha - dihydrotestosterone greater than progesterone = corticosterone greater than estradiol). AR was present in nuclear extracts, where greater than 80% of binding sites were occupied by endogenous ligand, but was not detectable in cytosol. On linear sucrose gradients, nuclear AR sedimented at 3-4 S in both low and high ionic-strength buffers and, by this and other criteria, was distinguishable from the nonreceptor androgen binding protein (ABP) of the same species. The diffuse distribution of AR in germinal and nongerminal (glandular) tissues at all developmental stages is consistent with a dual localization in Sertoli cells and Leydig cells, as previously reported in mammals, and further suggests a regulatory role of androgen throughout spermatogenesis.
Explore the source record for details and available documents.