A karyopherin acts in localized protein synthesis

Abstract

Multiple mechanisms are in place to regulate adequate synthesis of proteins, ranging from ways to ensure sequence fidelity, polypeptide folding and protein modification, to control of amounts and subcellular localization of the molecules. Some of these mechanisms act at the level of mRNA export and mRNA targeting. mRNA nuclear export consists of three coupled consecutive steps: (1) the packaging into messenger ribonucleoprotein (mRNP); (2) the transport through the nuclear pore complexes (NPCs); and (3) the directional release into the cytoplasm (reviewed in refs. 1 and 2). The subsequent targeting of mRNA to particular subcellular locations is common in asymmetric cell division in many eukaryotes (reviewed in refs. 3-5) and ensures that proteins are produced at the desired place. Recent studies in Saccharomyces cerevisiae suggest that Karyopherin Kap104p plays a role not only in mRNA export but also in bud-localized protein synthesis.6,7 In this report, we reflect on the possible mechanisms by which Kap104p links these events and hypothesize on a possible function of the localized protein synthesis. © 2010 Landes Bioscience.