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Lipid Phosphate Phosphatases 1 and 3 Are Localized in Distinct Lipid Rafts
- Source :
- The Journal of Biochemistry. 140:677-686
- Publication Year :
- 2006
- Publisher :
- Oxford University Press (OUP), 2006.
-
Abstract
- Lipid phosphate phosphatases (LPPs), integral membrane proteins with six transmembrane domains, dephosphorylate a variety of extracellular lipid phosphates. Although LPP3 is already known to bind to Triton X-100-insoluble rafts, we here report that LPP1 is also associated with lipid rafts distinct from those harboring LPP3. We found that LPP1 was Triton X-100-soluble, but CHAPS-insoluble in LNCaP cells endogenously expressing LPP1 and several LPP1 cDNA-transfected cells including NIH3T3 fibroblasts. In addition to the non-ionic detergent insolubility, LPP1 further possessed several properties formulated for raft-localizing proteins as follows: first, the CHAPS-insolubility was resistant to the actin-disrupting drug cytochalasin D; second, the CHAPS-insoluble LPP1 floated in an Optiprep density gradient; third, the CHAPS insolubility of LPP1 was lost by cholesterol depletion; and finally, the subcellular distribution pattern of LPP1 exclusively overlapped with that of a raft marker, cholera toxin B subunit. Interestingly, confocal microscopic analysis showed that LPP1 was distributed to membrane compartments distinct from those of LPP3. Analysis using various LPP1/LPP3 chimeras revealed that their first extracellular regions determine the different Triton X-100 solubilities. These results indicate that LPP1 and LPP3 are distributed in distinct lipid rafts that may provide unique microenvironments defining their non-redundant physiological functions.
- Subjects :
- Cytochalasin D
Octoxynol
Phosphatase
Phosphatidate Phosphatase
Biology
Biochemistry
Mice
chemistry.chemical_compound
Membrane Microdomains
Chaps
Chlorocebus aethiops
Extracellular
Animals
Humans
Molecular Biology
Lipid raft
Integral membrane protein
Microscopy, Confocal
Cholic Acids
General Medicine
Cell biology
Isoenzymes
Transmembrane domain
Solubility
chemistry
COS Cells
Triton X-100
NIH 3T3 Cells
Subjects
Details
- ISSN :
- 17562651 and 0021924X
- Volume :
- 140
- Database :
- OpenAIRE
- Journal :
- The Journal of Biochemistry
- Accession number :
- edsair.doi.dedup.....0c327a13d5e356a0c0ff3ea7a36b83a4