The gene encoding the C gamma catalytic subunit of cAMP-dependent protein kinase is a transcribed retroposon.
Three different catalytic isoforms of cAMP-dependent protein kinase have been identified (C alpha, C beta, and C gamma). We report the cloning and characterization of the human and rhesus monkey genes encoding the testis-specific C gamma subunit. The human C gamma gene is intronless with an open reading frame similar to the previously published cDNA sequence. The 3' and 5' flanking regions share high similarity with the C alpha nontranslated regions (82%) also outside the regions corresponding to the C gamma cDNA. The human gene is flanked by an Alu-related sequence in the 5'-end and there are insertions of two Alu-related sequences in the 3' nontranslated region. The observation that the C gamma gene is intronless and colinear with C alpha mRNA, together with the presence of remnants of a poly(A) tail and flanking direct repeats, indicates that the C gamma gene is a C alpha-derived retroposon. The 5' flanking region of this gene has a high G/C content and a putative TATA box situated at -138 compared to the translation initiation codon. Cloning and sequencing of a partial C gamma rhesus monkey gene demonstrate conservation of the sequence in primates. Northern analysis on isolated and fractionated human germ cells of testes from normal and estrogen-treated individuals demonstrates that the C gamma gene is expressed only in germ cells in the human testis. Our results indicate that the C gamma gene is a retroposon specifically transcribed in primate testicular germ cells.
Reinton
N
N
Institute of Medical Biochemistry, University of Oslo, Norway. nils.reinton@basalmed.uio.no
Haugen
T B
TB
Orstavik
S
S
Skålhegg
B S
BS
Hansson
V
V
Jahnsen
T
T
Taskén
K
K
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D017868:Cyclic AMP-Dependent Protein Kinases / Q000235:genetics*; D006801:Humans; D007527:Isoenzymes / Q000235:genetics; D008253:Macaca mulatta; D008297:Male; D008969:Molecular Sequence Data; D018626:Retroelements / Q000235:genetics*; D017422:Sequence Analysis, DNA; D013737:Testis / Q000201:enzymology; D014158:Transcription, Genetic
D007527:Isoenzymes; D018626:Retroelements; D017868:Cyclic AMP-Dependent Protein Kinases