Developmental expression of the protein kinase C substrate/binding protein (clone 72/SSeCKS) in rat testis identification as a scaffolding protein containing an A-kinase-anchoring domain which is expressed during late-stage spermatogenesis.
The coordinated interaction of kinases, phosphatases and other regulatory molecules with scaffolding proteins is emerging as a major theme in intracellular signaling networks. In this report we show that a cDNA isolated from a rat testis expression library by interactive cloning using the regulatory subunit (R) of a type-II protein kinase A (PKA) is identical with a previously characterized protein kinase C (PKC)-binding protein termed either clone 72 [Chapline, C., Mousseau, B., Ramsay, K., Duddy, S., Li, Y., Kiley, S. C. & Jaken, S. (1996) J. Biol. Chem. 271, 6417-6422] or SSeCKS [Lin, X., Tombler, E., B., Nelson, P.J., Ross, M. & Gelman, I.H. (1996) J. Biol. Chem. 271, 28430-28438]. Deletion mutagenesis demonstrated that amino acids 1495-1524 of clone 72/SSeCKS had the ability to interact with RII. Antibodies prepared against the recombinant protein recognized a 280/290-kDa doublet and a 240-kDa protein on Western blots of rat testis cytosolic and Triton X-100 extracts. Expression of clone 72/SSeCKS mRNA and protein levels was developmentally regulated in rat testis. Northern-blot analysis showed a dramatic increase in clone 72/SSeCKS-hybridizing mRNA starting 30 days after birth. Immunohistochemical examination showed high expression levels in elongating spermatids. Clone 72/SSeCKS was not detected in mature sperm. These studies suggest a role for clone 72/SSeCKS, a PKA/PKC scaffolding protein, during the process of spermiogenesis.
Erlichman
J
J
Department of Medicine, Albert Einstein College of Medicine, Bronx, NY, USA. erlichma@aecom.yu.edu
Gutierrez-Juarez
R
R
Zucker
S
S
Mei
X
X
Orr
G A
GA
D054758:A Kinase Anchor Proteins; D000375:Aging / Q000378:metabolism*; D000818:Animals; D001324:Autoantigens / Q000235:genetics; D018797:Cell Cycle Proteins; D003001:Cloning, Molecular; D054746:Cyclic AMP-Dependent Protein Kinase Type II; D017868:Cyclic AMP-Dependent Protein Kinases / Q000235:genetics / Q000378:metabolism*; D018076:DNA, Complementary; D018507:Gene Expression Regulation, Developmental; D015723:Gene Library; D008297:Male; D008934:Mitogens / Q000235:genetics* / Q000378:metabolism; D016297:Mutagenesis, Site-Directed; D011506:Proteins / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D011994:Recombinant Proteins / Q000378:metabolism; D017384:Sequence Deletion; D013091:Spermatogenesis / Q000502:physiology*; D013737:Testis / Q000254:growth & development / Q000378:metabolism*; D014158:Transcription, Genetic
D054758:A Kinase Anchor Proteins; C491162:AKAP12 protein, human; C102361:Akap12 protein, rat; D001324:Autoantigens; D018797:Cell Cycle Proteins; D018076:DNA, Complementary; D008934:Mitogens; D011506:Proteins; D012333:RNA, Messenger; D011994:Recombinant Proteins; D054746:Cyclic AMP-Dependent Protein Kinase Type II; D017868:Cyclic AMP-Dependent Protein Kinases