Identification of porcine fatty acid translocase: high-level transcript in intramuscular fat

Fatty acids translocase (FAT) is a transporter that facilitate long-chain fatty acids uptake as well as lipid accretion. To investigate the potential role of FAT in different adipose tissues, we investigated the cDNA structure of porcine FAT (pFAT) and analysed the tissue distribution of pFAT mRNA. The FAT mRNA expression profiles in the pre-adipocytes isolated from subcutaneous and intramuscular fat were also compared during cell differentiation. The results showed that 2389 bp porcine cDNA (DQ192230) had 87% homology with human FAT, 83% with mouse FAT, 82% with rat FAT and 67.5% with chicken FAT. Alignment of deduced amino acids sequence showed 82.4% homology with human FAT, 83.3% with mouse FAT and 85% with rat FAT. RT-PCR analysis revealed that the pFAT mRNA had a wide-spread expression in most tissues except for the brain. The higher level transcript was detected in visceral fat tissue by real-time quantitative RT-PCR. Interestingly, the pFAT mRNA expression level was dramatically increased in the primary culture pre-adipocytes derived from intramuscular fat and this consistent with the cellular lipid accretion. However, a sustained lower-level transcript was also found in the adipocytes from subcutaneous fat. The present study indicated that pFAT mRNA had a differential expression in subcutaneous, visceral and intramuscular fat depots. The data presented here provide further proof that pFAT might be involved in the modulation of the temporal and spatial fat depots.