PKCθII, a new isoform of protein kinase C specifically expressed in the seminiferous tubules of mouse testis
PKCθII, a new isoform of protein kinase C specifically expressed in the seminiferous tubules of mouse testis
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DOI：
10.1074/jbc.m104348200
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发表时间：
2001-09-28
影响因子：
4.8
通讯作者：
Kuroki, T
中科院分区：
文献类型：
--
作者：
Niino, YS;Irie, T;Kuroki, T
Protein kinase C (PKC) theta, a Ca2+-independent isoform of PKC, has been known to be expressed in skeletal muscle and T cells. In the present study, we isolated and characterized a smaller transcript expressed in the mouse testis, the cDNA of which is referred hereafter as PKC theta II and the original PKC theta as PKC thetaI. The cDNA clone of PKC theta II has 2184 base pairs and 464 amino acids in the possible open reading frame, consisting of the 5' unique sequence of 20 amino acids and the PKC thetaI sequence of 444 amino acids. Genomic DNA analysis revealed that transcription of PKC theta II is initiated from the PKC theta II-specific exon, which is located between exons 7 and 8 of the PKC theta gene, indicating that alternative splicing is the mechanism by which PKC theta II is generated. PKC theta II is expressed exclusively in the testis in an age-dependent manner with sexual maturation. In situ hybridization and reverse transcription-polymerase chain reaction of microdissected tissues clearly demonstrated that PKC theta II is expressed in the seminiferous tubules of the mouse testis. Consistent with its molecular structure lacking the C1 regulatory domain, PKC theta II is constitutively active as determined by an in vitro kinase assay, being independent of PKC activators, e.g. phosphatidylserine and phorbol ester. PKC theta II may play a crucial role in spermatogenesis or some related function of the testis.
