The poly(C) binding proteins (PCBPs) are encoded at five dispersed
loci in the mouse and human genomes. These proteins, which can
be divided into two groups, hnRNPs K/J and the αCPs
(αCP1-4), are linked by a common evolutionary history, a
shared triple KH domain configuration, and by their poly(C)
binding specificity. Given these conserved characteristics it
is remarkable to find a substantial diversity in PCBP functions.
The roles of these proteins in mRNA stabilization, translational
activation, and translational silencing suggest a complex and
diverse set of post-transcriptional control pathways. Their
additional putative functions in transcriptional control and
as structural components of important DNA-protein complexes
further support their remarkable structural and functional
versatility. Clearly the identification of additional binding
targets and delineation of corresponding control mechanisms
and effector pathways will establish highly informative models
for further exploration.