LAPTM4A interacts with hOCT2 and regulates its endocytotic recruitment.
Cell Mol Life Sci
; 68(24): 4079-90, 2011 Dec.
Article
in En
| MEDLINE
| ID: mdl-21553234
ABSTRACT
Human organic cation transporter 2 (hOCT2) is involved in the transport of endogenous and exogenous organic cations mainly in cells of the kidney and the brain. Here, we focus on the regulation of hOCT2 by direct protein-protein interaction. Screening within a mating-based split-ubiquitin-yeast-two-hybrid system (mBSUS) revealed the lysosomal-associated protein transmembrane 4 alpha (LAPTM4A) as a potential interacting protein. Interaction of LAPTM4A and hOCT2 was confirmed by pulldown assays, FRET microscopy analysis and immunofluorescence microscopy. Functionally, overexpression of LAPTM4A significantly decreased ASP(+) uptake in HEK293 cells stably transfected with hOCT2, suggesting a negative regulation of hOCT2-mediated transport. Furthermore, overexpression of LAPTM4A leads to a significantly decreased hOCT2 plasma membrane expression in surface biotinylation experiments. In addition, significant expression of LAPTM4A in human kidney was demonstrated by immunoblotting and immunofluorescence.In this work, LAPTM4A has been identified as interaction partner of hOCT2. LAPTM4A regulates the function of hOCT2 by influencing its trafficking to/from the cell membrane and processing it via the intracellular sorting machinery.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Membrane Transport Proteins
/
Organic Cation Transport Proteins
/
Endocytosis
Limits:
Humans
Language:
En
Journal:
Cell Mol Life Sci
Year:
2011
Document type:
Article