A GENERAL RNA-BINDING PROTEIN COMPLEX THAT INCLUDES THE CYTOSKELETON-ASSOCIATED PROTEIN MAP 1A

Association of mRNA with the cytoskeleton represents a fundamental asp ect of RNA physiology likely involved in mRNA transport, anchoring, tr anslation, and turnover. We report the initial characterization of a p rotein complex that binds RNA in a sequence-independent but size-depen dent manner in vitro. The complex includes a similar to 160-kDa protei n that is bound directly to mRNA and that appears to be either identic al or highly related to a similar to 1600-kDa protein that binds direc tly to mRNA in vivo. In addition, the microtubule-associated protein, MAP 1A, a cytoskeletal associated protein is a component of this compl ex. We suggest that the general attachment of mRNA to the cytoskeleton may be mediated, in part, through the formation of this ribonucleopro tein complex.