SUMO proteins are involved in the stress response during spermatogenesis and are localized to DNA double-strand breaks in germ cells.
Small ubiquitin-like modifiers (SUMO) proteins have been implicated in cellular stress response in different tissues, but whether sumoylation has a similar role during spermatogenesis is currently unknown. In this study, changes in the levels of both free SUMO isoforms and high-molecular weight (HMW) SUMO conjugates were monitored before and after the induction of different types of cellular stresses. Using cell lines and primary cells freshly isolated from mouse testes, significant changes were detected in the levels of SUMO1 and SUMO2/3 conjugates following short exposure of the cells to heat stress and oxidative stress. While high concentrations of H(2)O(2) caused an increase in protein sumoylation, low concentrations of H(2)O(2) mostly caused protein desumoylation. Immunofluorescence studies localized SUMO to the sites of DNA double-strand breaks in stressed germ cells and during meiotic recombination. To study the effect of oxidative stress in vivo, animals exposed to tobacco smoke for 12 weeks were used. Changes in sumoylation of HMW proteins were consistent with their oxidative damage in the tobacco-exposed mice. Our results are consistent with the important roles of different SUMO isoforms in stress responses in germ cells. Furthermore, this study identified topoisomerase 2 alpha as one of the targets of sumoylation during normal spermatogenesis and under stress.
Shrivastava
Vibha
V
Department of Biology, Stern College for Women, Yeshiva University, 245 Lexington Avenue, New York, New York 10016, USA.
Pekar
Marina
M
Grosser
Eliana
E
Im
Jay
J
Vigodner
Margarita
M
D000818:Animals; D000951:Antigens, Neoplasm / Q000032:analysis / Q000378:metabolism; D015153:Blotting, Western; D002460:Cell Line; D004247:DNA / Q000737:chemistry; D053903:DNA Breaks, Double-Stranded; D004250:DNA Topoisomerases, Type II / Q000032:analysis / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000032:analysis / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D006358:Hot Temperature; D006861:Hydrogen Peroxide / Q000008:administration & dosage; D008297:Male; D008540:Meiosis; D051379:Mice; D018384:Oxidative Stress / Q000502:physiology; D025842:SUMO-1 Protein / Q000032:analysis / Q000378:metabolism; D012708:Sertoli Cells / Q000737:chemistry; D025841:Small Ubiquitin-Related Modifier Proteins / Q000032:analysis* / Q000378:metabolism*; D012906:Smoke; D013091:Spermatogenesis / Q000502:physiology*; D013093:Spermatogonia / Q000737:chemistry; D013094:Spermatozoa / Q000737:chemistry* / Q000166:cytology; D013312:Stress, Physiological / Q000502:physiology*; D013737:Testis / Q000166:cytology; D014452:Ubiquitins / Q000032:analysis / Q000378:metabolism
D000951:Antigens, Neoplasm; D004268:DNA-Binding Proteins; D025842:SUMO-1 Protein; C515972:SUMO2 protein, mouse; D025841:Small Ubiquitin-Related Modifier Proteins; D012906:Smoke; C117908:Sumo3 protein, mouse; D014452:Ubiquitins; D004247:DNA; D006861:Hydrogen Peroxide; D004250:DNA Topoisomerases, Type II