High impact information on IST2

• In this study, we show that the COOH-terminal domain of Ist2p is necessary and sufficient to mediate SEC18-independent sorting when it is positioned at the COOH terminus of different integral membrane proteins and exposed to the cytoplasm [1].
• The yeast protein Ist2p, which is synthesized from a localized mRNA, travels from the ER to the plasma membrane via a novel route that operates independently of the formation of coat protein complex II-coated vesicles [1].
• In contrast to a PM-located hexose transporter (Hxt1p) that follows the standard secretory pathway, the trafficking of Ist2p is independent of myosin-mediated vesicular transport [2].
• Here, we show that localization of constitutively expressed IST2 mRNA is required for delivery of Ist2p to the PM of daughter, but not mother cells and that it does not result in daughter-specific Ist2p accumulation [2].
• Electrophoretic mapping of the STA and SGA genes is at present the only way to localize these genes, since glucoamylase repressor gene(s) (STA10, INH1 and/or IST2) are present in most laboratory strains of S. cerevisiae and the SGA phenotype is only detectable during sporulation [3].

Biological context of IST2

• Interaction among Btn1p, Btn2p, and Ist2p reveals potential interplay among the vacuole, amino acid levels, and ion homeostasis in the yeast Saccharomyces cerevisiae [4].

Anatomical context of IST2

• This sorting signal operates independently of targeting information in IST2 mRNA and sorting to the plasma membrane does not require She-mediated mRNA transport into daughter cells [5].

Other interactions of IST2

• Ist2 is probably involved in osmotolerance, Nog2p is a putative GTPase required for 60S ribosomal subunit maturation, but may also participate in mRNA splicing [6].
• We now report the biochemical and physical interactions of Btn2p with Ist2p, a plasma membrane protein that is thought to have a function in salt tolerance [4].

References