Myo4p and She3p are required for cortical ER inheritance in Saccharomyces cerevisiae

J Cell Biol. 2003 Dec 22;163(6):1255-66. doi: 10.1083/jcb.200304030.


Myo4p is a nonessential type V myosin required for the bud tip localization of ASH1 and IST2 mRNA. These mRNAs associate with Myo4p via the She2p and She3p proteins. She3p is an adaptor protein that links Myo4p to its cargo. She2p binds to ASH1 and IST2 mRNA, while She3p binds to both She2p and Myo4p. Here we show that Myo4p and She3p, but not She2p, are required for the inheritance of cortical ER in the budding yeast Saccharomyces cerevisiae. Consistent with this observation, we find that cortical ER inheritance is independent of mRNA transport. Cortical ER is a dynamic network that forms cytoplasmic tubular connections to the nuclear envelope. ER tubules failed to grow when actin polymerization was blocked with the drug latrunculin A (Lat-A). Additionally, a reduction in the number of cytoplasmic ER tubules was observed in Lat-A-treated and myo4Delta cells. Our results suggest that Myo4p and She3p facilitate the growth and orientation of ER tubules.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Actin Cytoskeleton / drug effects
  • Actin Cytoskeleton / metabolism
  • Bridged Bicyclo Compounds, Heterocyclic / pharmacology
  • Cell Division / physiology
  • Cytoplasmic Streaming / physiology
  • Endoplasmic Reticulum / metabolism*
  • Endoplasmic Reticulum / ultrastructure
  • Intracellular Membranes / metabolism
  • Intracellular Membranes / ultrastructure
  • Mutation / genetics
  • Myosin Heavy Chains / genetics
  • Myosin Heavy Chains / metabolism*
  • Myosin Type V / genetics
  • Myosin Type V / metabolism*
  • RNA, Messenger / metabolism
  • RNA-Binding Proteins / genetics
  • RNA-Binding Proteins / metabolism*
  • Saccharomyces cerevisiae / metabolism*
  • Saccharomyces cerevisiae / ultrastructure
  • Saccharomyces cerevisiae Proteins / genetics
  • Saccharomyces cerevisiae Proteins / metabolism*
  • Thiazoles / pharmacology
  • Thiazolidines


  • Bridged Bicyclo Compounds, Heterocyclic
  • Myo4 protein, S cerevisiae
  • RNA, Messenger
  • RNA-Binding Proteins
  • SHE3 protein, S cerevisiae
  • Saccharomyces cerevisiae Proteins
  • Thiazoles
  • Thiazolidines
  • Myosin Type V
  • Myosin Heavy Chains
  • latrunculin A