Ubiquitylation and developmental regulation of invariant surface protein expression in trypanosomes.

ABSTRACT: The cell surface of Trypanosoma brucei is dominated by the glycosylphosphatidylinositol-anchored variant surface glycoprotein (VSG), which is essential for immune evasion. VSG biosynthesis, trafficking, and turnover are well documented, but trans-membrane domain (TMD) proteins, including the invariant surface glycoproteins (ISGs), are less well characterized. Internalization and degradation of ISG65 depend on ubiquitylation of conserved cytoplasmic lysines. Using epitope-tagged ISG75 and reporter chimeric proteins bearing the cytoplasmic and trans-membrane regions of ISG75, together with multiple mutants with lysine-to-arginine mutations, we demonstrate that the cytoplasmic tail of ISG75 is both sufficient and necessary for endosomal targeting and degradation. The ISG75 chimeric reporter p

SUBMITTER: Leung KF 

PROVIDER: S-EPMC3147413 | biostudies-literature | 2011 Jul

REPOSITORIES: biostudies-literature