The liver X receptor alpha (
LXRα) is a ligand-inducible transcription factor that belongs to a member of the nuclear receptor superfamily. LXRα functions as a transcriptional regulator of several important genes involved in the metabolism of cholesterol, fatty acids, and glucose. We determined the nucleotide sequences of the porcine
LXRα cDNA by using full-length cDNA clones derived from porcine cDNA libraries. Two porcine
LXRα transcript variants that differed only in the 5'-untranslated region (5'-UTR) were identified, and designated as porcine
LXRα-
1 and
LXRα-
2. The length of the 5'-UTR of the porcine
LXRα-
1 is 183 bp, whereas that of
LXRα-
2 is 216 bp. Both transcripts have an identical 1344-bp putative protein-coding region that encodes 447 amino acids. The 38bp of 3'side of the 5'-UTR is identical between
LXRα-
1 and
LXRα-
2. The
LXRα-
1 is similar to the mRNA of porcine
LXRα (DQ059138) . The 5'-UTR of
LXRα-
1 is 34bp longer than that of DQ059138. The 5'-UTR sequence of
LXRa-
1 and DQ059138 is similar to the sequence of the exonl of the human
LXRα gene and the mouse
LXRα gene. The 54bp of the upstream region of the 5'-UTR of
LXRα-
2 is similar to the exon6 of human
ACP2 gene. By using RT-PCR, the expression of the porcine
LXRα-
1 transcript was detected in the liver, kidney, small intestine, heart, muscle, thymus, spleen, and brain, whereas the porcine
LXRα-
2 transcript was expressed in the thymus and spleen.
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