The valosin-containing protein (VCP) is a target of Akt signaling required for cell survival.
The serine/threonine kinase Akt is a key mediator of cell survival and growth, but its precise mechanism of action, and more specifically, the nature of its signaling partners largely remain to be elucidated. We show, using a proteomics-based approach, that the valosin-containing protein (VCP), a member of the AAA (ATPases associated with a variety of cellular activities) family, is a target of Akt signaling. SDS-PAGE of Akt co-immunoprecipitated proteins obtained from MCF-7 breast cancer cells revealed the increase of a 97-kDa band under Akt activation. Mass spectrometry analysis allowed the identification of VCP, and we have shown a serine/threonine phosphorylation on an Akt consensus site upon activation by growth factors. Site-directed mutagenesis identified Ser-351, Ser-745, and Ser-747 as Akt phosphorylation sites on VCP. Confocal microscopy indicated a co-localization between Akt and VCP upon Akt stimulation. Interestingly, small interfering RNA against VCP induced an inhibition of the growth factor-induced activation of NF-kappaB and a potent pro-apoptotic effect. Together, these data identify VCP as an essential target of Akt signaling.
ERI-8 INSERM, Growth factor signaling in breast cancer. Functional proteomics, University of Sciences and Technologies Lille, 59655 Villeneuve d'Ascq, France.
Franck
F
Vandermoere
Ikram
I
El Yazidi-Belkoura
Christian
C
Slomianny
Yohann
Y
Demont
Gabriel
G
Bidaux
Eric
E
Adriaenssens
Jérôme
J
Lemoine
Hubert
H
Hondermarck
D000251:Adenosine Triphosphatases; D017209:Apoptosis; D018797:Cell Cycle Proteins / Q000737:chemistry*; D045744:Cell Line, Tumor; D002470:Cell Survival; D006801:Humans; D013058:Mass Spectrometry; D016297:Mutagenesis, Site-Directed; D016328:NF-kappa B / Q000378:metabolism; D010766:Phosphorylation; D017434:Protein Structure, Tertiary; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000378:metabolism; D012694:Serine / Q000737:chemistry; D015398:Signal Transduction; D000074405:Valosin Containing Protein
D018797:Cell Cycle Proteins; D016328:NF-kappa B; D034741:RNA, Small Interfering; D012694:Serine; D051057:Proto-Oncogene Proteins c-akt; D000251:Adenosine Triphosphatases; C000614178:VCP protein, human; D000074405:Valosin Containing Protein