Roles of the actin cytoskeleton in structuring the cortical endoplasmic reticulum.
Huang, Daniel Wenwei.
Date of Issue2011
School of Biological Sciences
Temasek Life Sciences Laboratory
The actin cytoskeleton is the primary determinant of endoplasmic reticulum (ER) dynamics. The ER is a dynamic structure that undergoes constant rearrangement through tubule branching, ring closure and tubule sliding. This rearrangement is thought to be dependent on actin cytoskeleton in yeast. The actin cytoskeleton consists of three structures: actin cables, actin patches and actomyosin rings. However little is known about how the various actin structures contribute to the rearrangement and positioning of the cortical ER. Here, through the use of screening, genetic methods and conditional methods, we show the existence of actin-ER co-dynamics in interphase cells and how actin cables and type V myosins are essential in maintaining cortical ER distribution at the cell tips. We observed that the cortical ER was disrupted at the tips of the cell in a screen of actin mutants. Furthermore, the lack of actin cables and type V myosins resulted in the same disruption of cortical ER at the cell tips. Thus, our data further supports growing evidences of actin cables and type V myosins involvement in transportation of ER to various subcellular locations.