RNA localization in yeast: moving towards a mechanism.
RNA localization is a widely utilized strategy employed by cells to spatially restrict protein function. In Saccharomyces cerevisiae asymmetric sorting of mRNA to the bud has been reported for at least 24 mRNAs. The mechanism by which the mRNAs are trafficked to the bud, illustrated by ASH1 mRNA, involves recognition of cis-acting localization elements present in the mRNA by the RNA-binding protein, She2p. The She2p/mRNA complex subsequently associates with the myosin motor protein, Myo4p, through an adapter, She3p. This ribonucleoprotein complex is transported to the distal tip of the bud along polarized actin cables. While the mechanism by which ASH1 mRNA is anchored at the bud tip is unknown, current data point to a role for translation in this process, and the rate of translation of Ash1p during the transport phase is regulated by the cis-acting localization elements. Subcellular sorting of mRNA in yeast is not limited to the bud; certain mRNAs corresponding to nuclear-encoded mitochondrial proteins are specifically sorted to the proximity of mitochondria. Analogous to ASH1 mRNA localization, mitochondrial sorting requires cis-acting elements present in the mRNA, though trans-acting factors involved with this process remain to be identified. This review aims to discuss mechanistic details of mRNA localization in S. cerevisiae.
Gonsalvez
Graydon B
GB
Department of Genetics, Case Western Reserve University, 10900 Euclid Ave, Cleveland, OH 44106, USA. rlong@mcw.edu
Urbinati
Carl R
CR
Long
Roy M
RM
D016764:Cell Polarity / Q000502:physiology; D003599:Cytoskeleton / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D008928:Mitochondria / Q000378:metabolism*; D014176:Protein Biosynthesis / Q000235:genetics / Q000502:physiology*; D012333:RNA, Messenger / Q000378:metabolism*; D012097:Repressor Proteins / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*
C098733:ASH1 protein, S cerevisiae; D004268:DNA-Binding Proteins; D012333:RNA, Messenger; D012097:Repressor Proteins; D029701:Saccharomyces cerevisiae Proteins