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1.  The FERM Protein Yurt Is a Negative Regulatory Component of the Crumbs Complex that Controls Epithelial Polarity and Apical Membrane Size 
Developmental cell  2006;11(3):363-374.
Summary
The Crumbs (Crb) complex is a key regulator of epithelial cell architecture where it promotes apical membrane formation. Here, we show that binding of the FERM protein Yurt to the cytoplasmic domain of Crb is part of a negative-feedback loop that regulates Crb activity. Yurt is predominantly a basolateral protein but is recruited by Crb to apical membranes late during epithelial development. Loss of Yurt causes an expansion of the apical membrane in embryonic epithelia and photoreceptor cells similar to Crb overexpression and in contrast to loss of Crb. Analysis of yurt crb double mutants suggests that these genes function in one pathway and that yurt negatively regulates crb. We also show that the mammalian Yurt orthologs YMO1 and EHM2 bind to mammalian Crb proteins. We propose that Yurt is part of an evolutionary conserved negative-feedback mechanism that restricts Crb complex activity in promoting apical membrane formation.
doi:10.1016/j.devcel.2006.06.001
PMCID: PMC2834949  PMID: 16950127
2.  Essential function of Drosophila Sec6 in apical exocytosis of epithelial photoreceptor cells 
The Journal of Cell Biology  2005;169(4):635-646.
Polarized exocytosis plays a major role in development and cell differentiation but the mechanisms that target exocytosis to specific membrane domains in animal cells are still poorly understood. We characterized Drosophila Sec6, a component of the exocyst complex that is believed to tether secretory vesicles to specific plasma membrane sites. sec6 mutations cause cell lethality and disrupt plasma membrane growth. In developing photoreceptor cells (PRCs), Sec6 but not Sec5 or Sec8 shows accumulation at adherens junctions. In late PRCs, Sec6, Sec5, and Sec8 colocalize at the rhabdomere, the light sensing subdomain of the apical membrane. PRCs with reduced Sec6 function accumulate secretory vesicles and fail to transport proteins to the rhabdomere, but show normal localization of proteins to the apical stalk membrane and the basolateral membrane. Furthermore, we show that Rab11 forms a complex with Sec5 and that Sec5 interacts with Sec6 suggesting that the exocyst is a Rab11 effector that facilitates protein transport to the apical rhabdomere in Drosophila PRCs.
doi:10.1083/jcb.200410081
PMCID: PMC2171699  PMID: 15897260

Results 1-2 (2)