Association of a GPI-anchored protein with detergent-resistant membranes facilitates its trafficking through the early secretory pathway.
Exp Cell Res
; 315(2): 348-56, 2009 Jan 15.
Article
in En
| MEDLINE
| ID: mdl-19022244
ABSTRACT
Membrane microdomains are implicated in the trafficking and sorting of several membrane proteins. In particular GPI-anchored proteins cluster into Triton X-100 resistant, cholesterol- and sphingolipid-rich membrane microdomains and are sorted to the apical membrane. A growing body of evidence has pointed to the existence of other types of microdomains that are insoluble in detergents, such as Lubrol WX and Tween-20. Here, we report on the role of detergent-resistant membranes formed at early stages in the biosynthesis of membrane dipeptidase (MDP), a GPI-anchored protein, on its trafficking and sorting. Pulse-chase experiments revealed a retarded maturation rate of the GPI-anchor deficient mutant (MDPDeltaGPI) as compared to the wild type protein (wtMDP). However, Golgi to cell surface delivery rate did not show a significant difference between the two variants. On the other hand, early biosynthetic forms of wtMDP were partially insoluble in Tween-20, while MDPDeltaGPI was completely soluble. The lack of association of MDPDeltaGPI with detergent-resistant membranes prior to maturation in the Golgi and the reduction in its trafficking rate strongly suggest the existence of an early trafficking control mechanisms for membrane proteins operating at a level between the endoplasmic reticulum and the cis-Golgi.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Signal Transduction
/
Glycosylphosphatidylinositols
/
Membrane Microdomains
/
Dipeptidases
Type of study:
Risk_factors_studies
Limits:
Animals
Language:
En
Journal:
Exp Cell Res
Year:
2009
Type:
Article
Affiliation country:
Germany