C-Jun phosphorylation (Ser-63) in the testis of the lizard, Podarcis s. sicula.
Proto-oncogenes play an important role in the regulation of cellular growth and differentiation. C-Jun activity has been studied in the testis of a non mammalian vertebrate, the lizard Podarcis s. sicula, during two different periods: winter stasis and the breeding season. C-Jun protein was localized by immunocytochemistry in the cytoplasm of the spermatogonia (SPG) and stage I and II spermatocytes (SPC) during the winter stasis (from December until March), while the protein was present in the nuclei of the same cells during the active spermatogenic period (April/May). The different localization of c-Jun has been confirmed by Western blot and immunoprecipitation analysis. In addition, when Jun is present in the nuclear compartment, it is phosphorylated on Ser-63 and is complexed with Fos protein. These data suggest that the nuclear localization of the Jun protein in the SPG and stage I and II SPC, with strong phosphorylation on Ser-63 during the breeding period, could be the signal of increasing transcriptional activity in the lizard testis.
Chieffi
P
P
Dipartimento di Biologia e Patologia Cellulare e Molecolare 'L Califano', Università di Napoli 'Federico II', Naples, Italy. chieffi@unina.it
Picascia
A
A
Stanzione
R
R
Tramontano
D
D
D000818:Animals; D015153:Blotting, Western; D007124:Immunoenzyme Techniques; D008116:Lizards / Q000378:metabolism*; D008297:Male; D010766:Phosphorylation; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism; D016755:Proto-Oncogene Proteins c-jun / Q000378:metabolism*; D012621:Seasons; D013091:Spermatogenesis / Q000502:physiology; D013093:Spermatogonia / Q000378:metabolism; D013094:Spermatozoa / Q000378:metabolism; D013737:Testis / Q000378:metabolism*
D016760:Proto-Oncogene Proteins c-fos; D016755:Proto-Oncogene Proteins c-jun