title: Pathways for compartmentalizing protein synthesis in eukaryotic cells: the template-partitioning model.
abstract: mRNAs encoding signal sequences are translated on endoplasmic reticulum (ER) -- bound ribosomes, whereas mRNAs encoding cytosolic proteins are translated on cytosolic ribosomes. The partitioning of mRNAs to the ER occurs by positive selection; cytosolic ribosomes engaged in the translation of signal-sequence-bearing proteins are engaged by the signal-recognition particle (SRP) pathway and subsequently trafficked to the ER. Studies have demonstrated that, in addition to the SRP pathway, mRNAs encoding cytosolic proteins can also be partitioned to the ER, suggesting that RNA partitioning in the eukaryotic cell is a complex process requiring the activity of multiple RNA-partitioning pathways. In this review, key findings on this topic are discussed, and the template-partitioning model, describing a hypothetical mechanism for RNA partitioning in the eukaryotic cell, is proposed.
authors.affiliation: Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, USA. c.nicchitta@celbio.duke.edu
authors.forename: Christopher V
authors.initials: CV
authors.lastname: Nicchitta
authors.forename: Rachel S
authors.initials: RS
authors.lastname: Lerner
authors.forename: Samuel B
authors.initials: SB
authors.lastname: Stephens
authors.forename: Rebecca D
authors.initials: RD
authors.lastname: Dodd
authors.forename: Brook
authors.initials: B
authors.lastname: Pyhtila
mesh_terms: D000818:Animals; D004721:Endoplasmic Reticulum / Q000378:metabolism; D005057:Eukaryotic Cells / Q000378:metabolism*; D006801:Humans; D014176:Protein Biosynthesis / Q000502:physiology*; D012333:RNA, Messenger / Q000378:metabolism; D012270:Ribosomes / Q000378:metabolism; D018271:Signal Recognition Particle; D015398:Signal Transduction
chemical_list: D012333:RNA, Messenger; D018271:Signal Recognition Particle