Publications by authors named "Ting-Sung Hsieh"

The mammalian target of rapamycin complex 1 (mTORC1) integrates nutrients, growth factors, stress, and energy status to regulate cell growth and metabolism. Amino acids promote mTORC1 lysosomal localization and subsequent activation. However, the subcellular location or interacting proteins of mTORC1 under amino acid-deficient conditions is not completely understood.

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During infection, intracellular bacterial pathogens translocate a variety of effectors into host cells that modify host membrane trafficking for their benefit. We found a self-organizing system consisting of a bacterial phosphoinositide kinase and its opposing phosphatase that formed spatiotemporal patterns, including traveling waves, to remodel host cellular membranes. The effector MavQ, a phosphatidylinositol (PI) 3-kinase, was targeted to the endoplasmic reticulum (ER).

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The endoplasmic reticulum (ER) Ca sensor STIM1 forms oligomers and translocates to ER-plasma membrane (PM) junctions to activate store-operated Ca entry (SOCE) after ER Ca depletion. STIM1 also interacts with EB1 and dynamically tracks microtubule (MT) plus ends. Nevertheless, the role of STIM1-EB1 interaction in regulating SOCE remains unresolved.

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Endoplasmic reticulum-plasma membrane (ER-PM) junctions mediate crucial activities ranging from Ca signaling to lipid metabolism. Spatial organization of ER-PM junctions may modulate the extent and location of these cellular activities. However, the morphology and distribution of ER-PM junctions are not well characterized.

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Endoplasmic reticulum (ER)-plasma membrane (PM) junctions are highly conserved subcellular structures. Despite their importance in Ca(2+) signaling and lipid trafficking, the molecular mechanisms underlying the regulation and functions of ER-PM junctions remain unclear. By developing a genetically encoded marker that selectively monitors ER-PM junctions, we found that the connection between ER and PM was dynamically regulated by Ca(2+) signaling.

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Dynamic oscillation of the Min system in Escherichia coli determines the placement of the division plane at the midcell. In addition to stimulating MinD ATPase activity, we report here that MinE can directly interact with the membrane and this interaction contributes to the proper MinDE localization and dynamics. The N-terminal domain of MinE is involved in direct contact between MinE and the membranes that may subsequently be stabilized by the C-terminal domain of MinE.

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