Tissue distribution of porcine peroxisome proliferator-activated receptor alpha: detection of an alternatively spliced mRNA.
Peroxisome proliferator-activated receptor alpha (PPAR alpha) plays a key role in regulating the catabolic pathway of lipids in response to a variety of compounds named peroxisome proliferators (PPs). The cellular responses to PPs differ among mouse/rat and other species and actualize the study in swine, which show close resemblance to human lipid physiology and metabolism. We have isolated the cDNA containing the open reading frame of porcine PPAR alpha whose deduced amino acid sequence revealed an evolutionary distance to mouse/rat that could be implicated in causing the species-dependent response to PPs. Interestingly, an alternatively spliced PPAR alpha mRNA, lacking exon 5, was detected by reverse transcriptase-polymerase chain reaction in several porcine tissues. This deletion alters the reading frame and introduces a premature stop codon of PPAR alpha, presumably giving rise to a C-terminal truncated protein. We have also examined PPAR alpha expression by Northern blot analysis in tissues taken from pigs at three different stages of maturation, including two breeds that differ considerably in body composition and fat deposition. Porcine PPAR alpha was predominantly expressed in kidney and liver in mature individuals. When comparing piglets of a young age, a breed-specific tissue distribution of PPAR alpha mRNA was observed, particularly in liver and heart.
Sundvold
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Department of Animal Science, Agricultural University of Norway, Box 5025, 1432 Aas, Norway. hilde.sunvold@ihf.nlh.no
Grindflek
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Lien
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D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D019143:Evolution, Molecular; D007668:Kidney / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D008969:Molecular Sequence Data; D009206:Myocardium / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics; D018160:Receptors, Cytoplasmic and Nuclear / Q000235:genetics / Q000378:metabolism*; D016415:Sequence Alignment; D013045:Species Specificity; D013552:Swine; D014018:Tissue Distribution; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
D012333:RNA, Messenger; D018160:Receptors, Cytoplasmic and Nuclear; D014157:Transcription Factors