Proteomic characterization of lipid rafts markers from the rat intestinal brush border.
To assess intestinal lipid rafts functions through the characterization of their protein markers, we have isolated lipid rafts of rat mucosa either from the total membrane or purified brush-border membrane (BBM) by sucrose gradient fractionation after detergent treatment. In both membrane preparations, the floating fractions (4-5) were enriched in cholesterol, ganglioside GM1, and N aminopeptidase (NAP) known as intestinal lipid rafts markers. Based on MALDI-TOF/MS identification and simultaneous detection by immunoblotting, 12 proteins from BBM cleared from contaminants were selected as rafts markers. These proteins include several signaling/trafficking proteins belonging to the G protein family and the annexins as well as GPI-anchored proteins. Remarkably GP2, previously described as the pancreatic granule GPI-anchored protein, was found in intestinal lipid rafts. The proteomic strategy assayed on the intestine leads to the characterization of known (NAP, alkaline phosphatase, dipeptidyl aminopeptidase, annexin II, and galectin-4) and new (GP2, annexin IV, XIIIb, Galpha(q), Galpha(11), glutamate receptor, and GPCR 7) lipid rafts markers. Together our results indicate that some digestive enzymes, trafficking and signaling proteins may be functionally distributed in the intestine lipid rafts.
Université Paul Cézanne, Aix-Marseille III, Faculté des Sciences et Techniques de St Jérôme, Institut Méditerranéen de Recherche en Nutrition IMRN, UMR-INRA 1111, LCBA-LBBN, 13397 Marseille Cedex 20, France.
Hang Thi Thu
HT
Nguyen
Adda Berkane
AB
Amine
Daniel
D
Lafitte
Abdul A
AA
Waheed
Cendrine
C
Nicoletti
Claude
C
Villard
Marion
M
Létisse
Valérie
V
Deyris
Muriel
M
Rozière
Léopold
L
Tchiakpe
Comeau-Druet
CD
Danielle
Louis
L
Comeau
Abel
A
Hiol
D000818:Animals; D017306:Annexin A2 / Q000145:classification / Q000378:metabolism; D015415:Biomarkers; D003902:Detergents / Q000494:pharmacology; D058851:GPI-Linked Proteins; D037541:Galectin 4 / Q000378:metabolism; D017261:Glycosylphosphatidylinositols / Q000378:metabolism; D019791:Guanidine / Q000378:metabolism; D007422:Intestines / Q000166:cytology*; D008297:Male; D008562:Membrane Glycoproteins / Q000378:metabolism; D021962:Membrane Microdomains / Q000187:drug effects / Q000378:metabolism*; D016253:Microscopy, Immunoelectron; D008871:Microvilli / Q000187:drug effects / Q000378:metabolism*; D043265:Phosphatidylinositol Diacylglycerol-Lyase / Q000378:metabolism; D040901:Proteomics; D051381:Rats; D017208:Rats, Wistar; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D017306:Annexin A2; D015415:Biomarkers; D003902:Detergents; D058851:GPI-Linked Proteins; D037541:Galectin 4; D017261:Glycosylphosphatidylinositols; C066161:Gp2 protein, rat; D008562:Membrane Glycoproteins; D043265:Phosphatidylinositol Diacylglycerol-Lyase; D019791:Guanidine