Format

Send to

Choose Destination
Exp Cell Res. 2009 Jul 1;315(11):1953-63. doi: 10.1016/j.yexcr.2009.03.013. Epub 2009 Mar 25.

Mutation of juxtamembrane cysteines in the tetraspanin CD81 affects palmitoylation and alters interaction with other proteins at the cell surface.

Author information

1
Molecular, Cellular and Developmental Biology Program, Kansas State University, Manhattan, KS 66506, USA.

Abstract

Palmitoylation of tetraspanins affects protein-protein interactions, suggesting a key role in the assembly of the tetraspanin web. Since palmitoylation occurs on intracellular cysteine residues, we examined whether mutating these residues in the human tetraspanin CD81 would affect the association of CD81 with other surface membrane proteins. Mutation of at least six of the eight juxtamembrane cysteines was required to completely eliminate detectable CD81 palmitoylation, indicating that several sites can be palmitoylated. Interestingly, these mutated proteins exhibited reduced cell surface detection by antibody compared to wild-type CD81, but this was not due to differences in the level of protein expression, trafficking to the cell surface, protein stability, or anti-CD81 antibody binding affinity. Instead, the mutant CD81 proteins appeared to be partially hidden from detection by anti-CD81 antibody, presumably due to altered interactions with other proteins at the cell surface. Associations with the known CD81-interacting proteins CD9 and EWI-2 were also impaired with the mutant CD81 proteins. Taken together, these findings indicate that mutation of juxtamembrane cysteines alters the interaction of CD81 with other proteins, either because of reduced palmitoylation, structural alterations in the mutant proteins, or a combination of both factors, and this affects the CD81 microenvironment on the cell surface.

PMID:
19328198
PMCID:
PMC2785499
DOI:
10.1016/j.yexcr.2009.03.013
[Indexed for MEDLINE]
Free PMC Article

Publication types, MeSH terms, Substances, Grant support

Publication types

MeSH terms

Substances

Grant support

Supplemental Content

Full text links

Icon for Elsevier Science Icon for PubMed Central
Loading ...
Support Center