Intracellular Trafficking Of Connexin 43 (Cx43) And Gap Junction Formation In Leiomyosarcoma Cells Following Interruption With Brefeldin A And Cycloheximide

Date of Graduation

Summer 2006

Degree

Master of Science in Cell and Molecular Biology

Department

Biomedical Sciences

Committee Chair

E Hendrix

Abstract

Gap junction formation is a single step in a series of regulated cellular events that includes connexin 43 (Cx43) expression, intracellular trafficking and posttranslational modification. Gap junction formation has been linked to certain physiological changes associated with the presumptive cellular transfer of small single molecules. Reports of Cx43 trafficking to date support the idea that Cx43 follows a single trafficking pathway. The purpose of this study is to test this hypothesis by examining Xc43 intracellular trafficking in leimomyosarcoma cells in which typical trafficking had been perturbed by the use of Brefeldin A and cycloheximide. SK-UT-1 cells were previously found to express relatively high concentrations of cx43 with intracellular trafficking patterns similar to that observed in vivo. Cells were cultured in media containing cycloheximide or Brefeldin A at various concentrations for 1 to 3 hours, and then cultured in fresh media without additives for an additional 12 hours. Medium to large vesicles containing immunopositive material were observed in cells cultured in Brefeldin A. These vesicles however, were smaller and confined to perinuclear regions following culture in control media. Immunopositive material was not observed in cells immediately following culture in the presence of cycloheximide, but appeared to be diffusely distributed throughout the cytoplasm. These results support the idea that the pattern of Cx43 intracellular trafficking, following interruption, will attempt to resume a predetermined pathway rather than to follow an alternative pathway.

Keywords

gap junction, connexin 43, Brefeldin A, cycloheximide, trafficking

Subject Categories

Medical Molecular Biology

Copyright

© Tammy S. Welchert

Citation-only

Dissertation/Thesis

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