| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Regular Article |
-s, Localizes to Sperm Midpiece1
a Institute of Medical Biochemistry, University of Oslo, N-0317 Oslo, Norway
b Andrology Laboratory, Department of Gynecology and Obstetrics, The National Hospital, N-0027 Oslo, Norway
c
ABSTRACT
Using rapid amplification of cDNA ends, a cDNA encoding a novel splice variant of the human C
catalytic subunit of cAMP-dependent protein kinase (PKA) was identified. The novel isoform differed only in the N-terminal part of the deduced amino acid sequence, corresponding to the part encoded by exon 1 in the previously characterized murine C gene. Sequence comparison revealed similarity to an ovine C variant characterized by protein purification and micropeptide sequencing, C-s, identifying the cloned human cDNA as the C-s isoform. The C-s mRNA was expressed exclusively in human testis and expression in isolated human pachytene spermatocytes was demonstrated. The C-s protein was present in ejaculated human sperm, and immunofluorescent labeling with a C-s-specific antibody indicated that C-s was localized in the midpiece region of the spermatozoon. The majority of C-s was particulate and could not be released from the sperm midpiece by cAMP treatment alone. Furthermore, detergent extraction solubilized approximately two-thirds of the C-s pool, indicating interaction both with detergent-resistant cytoskeletal and membrane structures. In addition, we recently identified the regulatory subunit isoforms RI, RII, and an A-kinase anchoring protein, hAKAP220 in this region in sperm that could target C-s. This novel C-s splice variant appeared to have an independent anchor in the human sperm midpiece as it could not be completely solubilized even in the presence of both detergent and cAMP.
1 This work was supported by the Norwegian Cancer Society, the Norwegian Research Council, Anders Jahres Foundation for the Promotion of Science, and NOVO Nordic Research Foundation Committee.
2 Correspondence: Bjørn S. Skålhegg, Institute of Medical Biochemistry, University of Oslo, P.O. Box 1112 Blindern, N-0317 Oslo, Norway. FAX: 47 22 85 14 97; bjorn.skaalhegg{at}basalmed.uio.no
This article has been cited by other articles:
|
|
 |
|
  K. TASKEN and E. M. AANDAHL Localized Effects of cAMP Mediated by Distinct Routes of Protein Kinase A Physiol Rev, January 1, 2004; 84(1): 137 - 167. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 G. Wennemuth, A. E. Carlson, A. J. Harper, and D. F. Babcock Bicarbonate actions on flagellar and Ca2+-channel responses: initial events in sperm activation Development, April 1, 2003; 130(7): 1317 - 1326. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. M. Niswender, R. W. Ishihara, L. M. Judge, C. Zhang, K. M. Shokat, and G. S. McKnight Protein Engineering of Protein Kinase A Catalytic Subunits Results in the Acquisition of Novel Inhibitor Sensitivity J. Biol. Chem., August 2, 2002; 277(32): 28916 - 28922. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 B. S. Skalhegg, Y. Huang, T. Su, R. L. Idzerda, G. S. McKnight, and K. A. Burton Mutation of the C{alpha} Subunit of PKA Leads to Growth Retardation and Sperm Dysfunction Mol. Endocrinol., March 1, 2002; 16(3): 630 - 639. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. T. San Agustin and G. B. Witman Differential Expression of the Cs and C{{alpha}}1 Isoforms of the Catalytic Subunit of Cyclic 3',5'-Adenosine Monophosphate-Dependent Protein Kinase Testicular Cells Biol Reprod, July 1, 2001; 65(1): 151 - 164. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
