Members of the fatty acid-binding protein family inhibit cell-free protein synthesis.

Fatty acid-binding proteins (FABPs) are 15-kDa cytosolic proteins which are involved in the intracellular binding and targeting of fatty acids. Some members have been implicated in the regulation of cell growth and differentiation. In this study we investigated the effect of a series of FABPs and heart FABP (H-FABP) mutants on cell-free protein synthesis. Human myelin, intestinal, heart and brain FABP showed a dose-dependent inhibition of in vitro mRNA translation. Adipocyte, liver and epidermal types had no effect. The inhibition was not influenced by delipidation and for H-FABP mutants not related to their affinity for fatty acids. Our results indicate that some FABPs may modulate cell growth and/or differentiation by inhibition of protein synthesis.