Expression of Prohibitin in Rat Seminiferous Epithelium1

Abstract

Subtractive hybridization was used to isolate cDNAs highly expressed in stages IX-XI of the cycle of the seminiferous epithelium in the rat. One of the cloned cDNAs was sequenced and shown to be homologous to a previously described cDNA encoding rat prohibitin. Northern blot analyses showed that 1.9- and 1.2-kb transcripts were present in Sertoli cells whereas 1.5-, 1.2-, and 0.7-kb transcripts were expressed in germ cells. Western blot analyses with anti-peptide antibody to prohibitin revealed only a single 30-kDa protein in testis. Immunocytochemistry demonstrated that prohibitin protein was expressed constitutively in adult Leydig cells and Sertoli cells at all stages. Immunoreactivity of prohibition was very low in preleptotene spermatocytes, very high in leptotene spermatocytes, and very low in zygotene spermatocytes. In pachytene spermatocytes, immunoreactivity was very high in stages VII-XI and was minimal during stages XII and XIV. No protein was detected in spermatogonia and spermatocytes undergoing mitotic and meiotic divisions, respectively. These studies show that the prohibitin gene is expressed differentially in testis. The expression pattern of the prohibitin gene in rat testis appears to correlate with a proposed antiproliferative role of prohibitin.

The Mitochondrial Prohibitin Complex Is Essential for Embryonic Viability and Germline Function in Caenorhabditis elegans

“…It is known that prohibitins are more expressed in proliferating than in nonproliferating cells of the same type, and mammalian tumor cells have increased levels of PHB proteins (18). In testis, PHB proteins are expressed during times of proliferation/differentiation but are lost entirely from the mature sperm (18,36,37). Therefore, proliferating undifferentiated cells might be particularly susceptible to the lack of prohibitins.…”

Millions of Years of Evolution Preserved: A Comprehensive Catalog of the Processed Pseudogenes in the Human Genome

“…In fact, the existence of multiple copies of processed pseudogenes can be used as ipso facto evidence for gene expression in the germ-line or early embryo cells. For several other genes listed in Table 3, we have searched the literature and verified that they are, indeed, expressed at various stages of spermatogenesis: P05092 (Wine et al 1997), P04406 (Welch et al 2000), P09651 (Kamma et al 1995), P06748 (Shackleford et al 2001), P06351 (Bramlage et al 1997), and P35232 (Choongkittaworn et al 1993). …”

Prohibitins, Stomatins, and Plant Disease Response Genes Compose a Protein Superfamily That Controls Cell Proliferation, Ion Channel Regulation, and Death

“…Prohibitins negatively control the cell cycle in the early G 1 phase and specifically inhibit initiation of DNA synthesis (8,9). Prohibitin genes appear to be expressed in many tissues and organisms, but with some modulation of expression consistent with a role in the cell cycle (7,8,10). Mutations or deletions of prohibitin are linked to some human breast and ovarian cancers, supporting the idea that prohibitin suppresses tumors as part of its antiproliferative function involving cell cycle control (11)(12)(13).…”