Posttranscriptional regulation of ATP-binding cassette transporter A1 in lipid metabolism.

Aim: Several lines of evidence have shown that posttranscriptional regulations play an important role in the modulation of ATP-binding cassette transporter A1 (ABCA1) expression and function.

Results: The clearance of ABCA1 mRNA as well as the trafficking, stability, degradation, and activity of the ABCA1 protein are regulated by diverse posttranscriptional mechanisms. ABCA1 mRNA clearance is induced by several microRNAs that result in translational repression and reduction of ABCA1 protein expression. Intracellular ABCA1 trafficking is enhanced toward the plasma membrane, leading to an elevation of cell-surface localization, where the majority of the cholesterol efflux activity occurs. The ABCA1 protein turnover is rapid via calpain-mediated degradation and ubiquitin-mediated degradation. Various modulators retard ABCA1 protein clearance, which raises ABCA1 protein levels. The activity of ABCA1 can also be altered by a few molecules that do not affect ABCA1 protein expression.

Conclusion: In this review, we summarize the advances in the knowledge of ABCA1 posttranscriptional regulation, which is warranted to better understand the role of ABCA1 in reverse cholesterol transport, lipid metabolism, and atherosclerosis.