Effects of c-Myc and TGF-Alpha on Polarized Membrane Traffic
Abstract
In polarized epithelial cells, components of the membrane fusion machinery, the t-SNAREs syntaxin 2, 3, 4 and SNAP-23 are differentially localized at the apical and/or basolateral plasma membrane domains. Surprisingly, all of these t-SNAREs redistribute to intracellular locations when cells lose their cellular polarity during mammary carcinogenesis. Apical SNAREs re-localize to the previously characterized vacuolar apical compartment (VAC) while basolateral SNAREs redistribute to a novel organelle that appears to be the basolateral equivalent of the VAC. Both intracellular plasma membrane compartments' are associated with the actin cytoskeleton and receive membrane traffic from cognate apical or basolateral pathways, respectively. These findings demonstrate a fundamental shift in plasma membrane traffic towards intracellular compartments while protein sorting is preserved when epithelial cells lose their cell polarity.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1999
- Accession Number
- ADA382519
Entities
People
- Keith E. Mostov
- Y. Altschuler
Organizations
- University of California, San Francisco