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Proteomic analysis of p38α mitogen‐activated protein kinase‐regulated changes in membrane fractions of RAS‐transformed fibroblasts
Author(s) -
Alfonso Patricia,
Dolado Ignacio,
Swat Aneta,
Núñez Antonio,
Cuadrado Ana,
Nebreda Angel R.,
Casal J. Ignacio
Publication year - 2006
Publication title -
proteomics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.26
H-Index - 167
eISSN - 1615-9861
pISSN - 1615-9853
DOI - 10.1002/pmic.200500350
Subject(s) - prohibitin , biology , carcinogenesis , microbiology and biotechnology , protein kinase a , signal transduction , kinase , protein disulfide isomerase , proteomics , p38 mitogen activated protein kinases , biochemistry , mitochondrion , endoplasmic reticulum , gene
Oncogenic Ras signaling has been long known to play an important role in tumorigenesis and human cancer. In this report, we have used the sensitive 2‐D‐DIGE coupled to MS for the identification of proteins differentially expressed at the cell membrane level between oncogenic H‐RasV12‐transformed wild‐type and p38α‐deficient mouse embryo fibroblasts (MEFs). Following trifluoroethanol solubilization, 76 proteins were found to be differentially regulated. After PMF, 63 spots containing 42 different proteins were unequivocally identified by MALDI‐TOF MS coupled with database interrogation. As expected, many of them were membrane proteins. Six proteins were selected for further validation studies based on their potential functional link with malignant transformation and signal transduction. These were prohibitin (PHB), protein disulfide isomerase 3 (PDIA3), focal adhesion kinase 2 (FAK2), c‐GMP dependent protein kinase 2 (KGP2), NADH‐ubiquinone oxidoreductase 30 kDa subunit (NUGM) and translationally controlled tumor protein (TCTP). All these proteins were up‐regulated in the membranes of H‐RasV12‐transformed p38α‐/‐cells, except for prohibitin, which was down‐regulated. An excellent correlation was found between DIGE results and Western blot studies, indicating the reliability of the 2‐D‐DIGE analysis. The available evidence about the putative function of the identified proteins supports the emerging role of p38α as a negative regulator of tumorigenesis. Further studies are in progress to elucidate the implications of these findings in the regulation of H‐Ras‐induced transformation by p38α signaling.