double-stranded RNA binding motif of APOBEC1 complementation factor (A1CF), RNA-binding protein 46 (RBM46) and similar proteins
The family includes two dsRNA-binding motif-containing proteins, A1CF and RBM46. A1CF (also known as APOBEC1-stimulating protein) is an essential component of the apolipoprotein B mRNA editing enzyme complex which is responsible for the posttranscriptional editing of a CAA codon for Gln to a UAA codon for stop in APOB mRNA. A1CF binds to APOB mRNA and is probably responsible for docking the catalytic subunit, APOBEC1, to the mRNA to allow it to deaminate its target cytosine. RBM46 (also called cancer/testis antigen 68 (CT68), or RNA-binding motif protein 46) plays a novel role in the regulation of embryonic stem cell (ESC) differentiation by regulating the degradation of beta-catenin mRNA. It also regulates trophectoderm specification by stabilizing Cdx2 mRNA in early mouse embryos. Members of this family contain three RNA recognition motifs (RRMs) and a C-terminal double-stranded RNA binding motif (DSRM) that is not sequence specific, but highly specific for dsRNAs of various origin and structure.