Poly(ADP-ribosylation) of nuclear proteins in rat testis correlates with active spermatogenesis.
Poly(ADP-ribosylation) of nuclear proteins has been investigated in rat testis under different experimental conditions to determine whether it is associated with somatic or germinal cells. Isolated, intact nuclei were incubated with [14C]NAD and extracted sequentially with 5% HClO4 and 0.25 M HCl, and labelled soluble proteins were analysed by reverse-phase high-performance liquid chromatography and acetic acid-urea polyacrylamide gel electrophoresis (pH 2.9). Results show that in normal adult testis a major acceptor protein for poly(ADP-ribose) in HClO4 extracts is the tissue-specific histone, H1t. Core histones and three proteins (alpha, beta and gamma) with low mobility on acetic acid-urea gels were the major acceptors identified in HCl extracts. Poly(ADP-ribosylation) of all the aforementioned proteins is very low in isolated intact nuclei of testis from 8-day-old animals (only spermatogonia present in seminiferous tubules), increases significantly by 16-day (pachytene spermatocytes appear) and reaches adult proportions by 32 days (condensing spermatids present). In the nuclei from cryptorchid testes, poly(ADP-ribosylation) of nuclear proteins resembles 8-day-old testis. It is concluded that (a) poly(ADP-ribosylation) of nuclear proteins in rat testis is closely correlated with spermatogenesis and can be inferred that is particularly active in the early stages of meiosis; (b) testis-specific proteins (histone H1t and low mobility proteins, alpha, beta and gamma) are poly(ADP-ribosylated) to higher specific radioactivity than somatic histones.
Quesada
P
P
Dipartimento di Chimica Organica e Biologica, Università di Napoli, Naples, Italy.
Farina
B
B
Jones
R
R
D000367:Age Factors; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D006609:High Mobility Group Proteins / Q000378:metabolism; D006657:Histones / Q000378:metabolism; D008297:Male; D008540:Meiosis; D009687:Nuclear Proteins / Q000378:metabolism*; D009702:Nucleoside Diphosphate Sugars / Q000378:metabolism*; D011064:Poly Adenosine Diphosphate Ribose / Q000378:metabolism*; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism*; D011499:Protein Processing, Post-Translational; D051381:Rats; D013091:Spermatogenesis; D013737:Testis / Q000378:metabolism*
D006609:High Mobility Group Proteins; D006657:Histones; D009687:Nuclear Proteins; D009702:Nucleoside Diphosphate Sugars; D011064:Poly Adenosine Diphosphate Ribose; D011065:Poly(ADP-ribose) Polymerases