Alternative splicing of the human diacylglycerol kinase zeta gene in muscle.
Diacylglycerol can function as a second messenger, and one mechanism for the attenuation of this signal is its conversion to phosphatidic acid, which is catalyzed by diacylglycerol kinase (DGK). We screened a cDNA library from human skeletal muscle and isolated two DGKzeta cDNAs that differed from the 3.5-kb clone originally identified in endothelial cells. One transcript, which was 3.4 kb long, was shown to be nonfunctional; it had a 77-bp deletion that included the translation initiation site. The other was 4.1 kb long with a unique 5' sequence of 853 bp. We also isolated a genomic clone of DGKzeta and determined its organization and location; it contains 32 exons, spans approximately 50 kb of genomic sequence, and maps to chromosome 11p11.2. The protein encoded by the 4.1-kb transcript contains two cysteine-rich regions, a catalytic domain, and ankyrin repeats like the endothelial form of DGKzeta, as well as a unique N-terminal domain. The coding sequence was shown to be derived from alternative splicing of the DGKzeta gene. In cells transfected with the 4.1-kb clone, we detected a 130-kDa protein with an antibody to DGKzeta and demonstrated that it was localized predominantly in the nucleus. We conclude that alternative splicing generates tissue-specific variants of DGKzeta that share some properties but may have unique ones as well.
Ding
L
L
Huntsman Cancer Institute, University of Utah, Salt Lake City, UT 84112, USA.
Bunting
M
M
Topham
M K
MK
McIntyre
T M
TM
Zimmerman
G A
GA
Prescott
S M
SM
D017398:Alternative Splicing; D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D019852:Diacylglycerol Kinase; D005091:Exons; D006801:Humans; D007438:Introns; D008969:Molecular Sequence Data; D008970:Molecular Weight; D018482:Muscle, Skeletal / Q000201:enzymology*; D009928:Organ Specificity; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics*; D016133:Polymerase Chain Reaction; D014176:Protein Biosynthesis; D017384:Sequence Deletion; D014158:Transcription, Genetic
D017853:Phosphotransferases (Alcohol Group Acceptor); D019852:Diacylglycerol Kinase