TY  - GEN
T1  - Daughter cell-targeted mRNAs can achieve segregation without the universal Endoplasmic Reticulum docker She2p
AU  - Samardak, Kseniya
AU  - Moriel-Carretero, María
DO  - 10.17912/micropub.biology.000458
UR  - http://beta.micropublication.org/journals/biology/micropub-biology-000458/
AB  - The establishment of cell polarity in eukaryotes involves the asymmetric distribution of messenger RNAs (mRNAs). In Saccharomyces cerevisiae, polarization leads to the budding of daughter cells, and more than 30 mRNAs subjected to selective targeting toward the bud tip have been characterized (Shepard et al. 2003; Aronov et al. 2007). Different mRNAs are segregated at different cell cycle stages, which is mostly dictated by their expression profiles. This way, mRNAs such as WSC2, IST2 or EAR1 are delivered during S / G2 phases, when the bud starts to emerge, while others, such as ASH1, are dispatched late during mitosis (Shepard et al. 2003; Fundakowski et al. 2012). Importantly, segregation of “early” mRNAs is coupled to, and dependent on, the simultaneous segregation of the endoplasmic reticulum (ER) toward the daughter cell (Figure 1A, left panel), while late-segregating mRNAs are not dependent on ER inheritance (Figure 1A, right panel) (Fundakowski et al. 2012). In both cases though, the trafficking of these mRNAs requests the myosin Myo4p, which promotes transport along actin filaments, and the adaptor protein She3p (Münchow et al. 1999) (Figure 1A). Using the mitosis-specific ASH1 mRNA as a model, a third, RNA-binding protein, She2p, was implicated as part of this “locasome” complex, its task being that of bridging the mRNA to the motor (Münchow et al. 1999; Bohl et al. 2000; Long et al. 2000; Takizawa and Vale 2000). Both the classical model ASH1 mRNA and 22 newly identified polarized mRNAs were found to be dependent on She2p for segregation (Bertrand et al. 1998; Shepard et al. 2003), and additional, asymmetrically distributed mRNAs, involved in polarity and exocytosis, were seen to co-fractionate with She2p (Aronov et al. 2007). Together, this has led to the general view that She2p is the universal factor docking mRNAs destined for the daughter cell at the Myo4p-She3p transporting complex. What is more, in the case of S-phase-segregating mRNAs, She2p is proposed to couple mRNA distribution and ER inheritance through its ER membrane-binding properties (Genz et al. 2013) (Figure 1A, left panel).
PY  - 2021
JO  - microPublication Biology
ER  -