RNA


REVIEWREVIEW

The poly(C)-binding proteins: A multiplicity of functions and a search for mechanisms


ALEKSANDR V.  MAKEYEV  a1 and STEPHEN A.  LIEBHABER  a1 c1
a1 Departments of Genetics and Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104, USA

Abstract

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 [alpha]CPs ([alpha]CP1-4), 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.

(Received August 30 2001)
(Revised October 16 2001)
(Accepted December 21 2001)


Key Words: [alpha]CP; hnRNP K; mRNA stability; mRNA translation; poly(C) binding proteins; post-transcriptional controls.

Correspondence:
c1 Reprint requests to: Dr. Stephen A. Liebhaber, University of Pennsylvania School of Medicine, Department of Genetics, CRB—Room 428, 415 Curie Blvd., Philadelphia, Pennsylvania 19104-6148, USA; e-mail: liebhabe@mail.med.upenn.edu.