Title

Differential expression of the C(s) and Calpha1 isoforms of the catalytic subunit of cyclic 3',5'-adenosine monophosphate-dependent protein kinase testicular cells

UMMS Affiliation

Department of Cell Biology; Program in Molecular Medicine

Date

6-23-2001

Document Type

Article

Subjects

Animals; Antibody Specificity; Blotting, Western; Cyclic AMP-Dependent Protein Kinases; Fluorescent Antibody Technique; Isoenzymes; Male; Mice; Microscopy, Confocal; Sheep; Testis

Disciplines

Life Sciences | Medicine and Health Sciences

Abstract

The amino terminus of the sperm cAMP-dependent protein kinase catalytic subunit (termed C(s)) differs from that of the Calpha1 isoform expressed in most tissues due to the use of alternative transcripts of the Calpha gene. Both Calpha1 and C(s) transcripts are present in testis; C(s) is expressed specifically in spermatogenic cells and is the only C isoform detected in mature sperm. Immunohistochemistry of mouse testis using antibodies specific for C(s) and Calpha1 now shows that Calpha1 is present in somatic testicular cells, spermatogonia, and preleptotene spermatocytes but not in cells that are in later stages of spermatogenesis. In contrast, C(s) is expressed only in midpachytene and later stage spermatocytes and in spermatids. Therefore, C(s) and Calpha1 expression do not overlap. Immunofluorescence microscopic localization of C(s) in murine and ovine sperm reveals that C(s) is located primarily in sperm tail components, including the midpiece mitochondria and the axoneme. Quantitative analysis of Western blots indicates that individual ovine sperm contain approximately 4 x 10(5) molecules of C(s), a seemingly large number for a protein that acts catalytically.

Rights and Permissions

Citation: Biol Reprod. 2001 Jul;65(1):151-64.

Related Resources

Link to article in PubMed

Journal Title

Biology of reproduction

PubMed ID

11420235