Para acceder a los documentos con el texto completo, por favor, siga el siguiente enlace: http://hdl.handle.net/2445/56363

Oncogenic K-Ras segregates at spatially distinct plasma membrane signaling platforms according to its phosphorylation status
Barceló, Carles; Paco, Noelia; Beckett. Alison J.; Alvarez-Moya, Blanca; Garrido, Eduard; Gelabert, Mariona; Tebar Ramon, Francesc; Jaumot i Pijoan, Montserrat; Prior, Ian; Agell i Jané, Neus
Universitat de Barcelona
Activating mutations in the K-Ras small GTPase are extensively found in human tumors. Although these mutations induce the generation of a constitutively GTP-loaded, active form of K-Ras, phosphorylation at Ser181 within the C-terminal hypervariable region can modulate oncogenic K-Ras function without affecting the in vitro affinity for its effector Raf-1. In striking contrast, K-Ras phosphorylated at Ser181 shows increased interaction in cells with the active form of Raf-1 and with p110α, the catalytic subunit of PI 3-kinase. Because the majority of phosphorylated K-Ras is located at the plasma membrane, different localization within this membrane according to the phosphorylation status was explored. Density-gradient fractionation of the plasma membrane in the absence of detergents showed segregation of K-Ras mutants that carry a phosphomimetic or unphosphorylatable serine residue (S181D or S181A, respectively). Moreover, statistical analysis of immunoelectron microscopy showed that both phosphorylation mutants form distinct nanoclusters that do not overlap. Finally, induction of oncogenic K-Ras phosphorylation - by activation of protein kinase C (PKC) - increased its co-clustering with the phosphomimetic K-Ras mutant, whereas (when PKC is inhibited) non-phosphorylated oncogenic K-Ras clusters with the non-phosphorylatable K-Ras mutant. Most interestingly, PI 3-kinase (p110α) was found in phosphorylated K-Ras nanoclusters but not in non-phosphorylated K-Ras nanoclusters. In conclusion, our data provide - for the first time - evidence that PKC-dependent phosphorylation of oncogenic K-Ras induced its segregation in spatially distinct nanoclusters at the plasma membrane that, in turn, favor activation of Raf-1 and PI 3-kinase.
Transport biològic
Proteïnes
Tumors
Biologia molecular
Biological transport
Proteins
Tumors
Molecular biology
(c) Barceló, C. et al., 2013
Artículo
info:eu-repo/semantics/acceptedVersion
The Company of Biologists
         

Mostrar el registro completo del ítem

Documentos relacionados

Otros documentos del mismo autor/a

Barceló, Carles; Paco, Noelia; Morell, Mireia; Alvarez-Moya, Blanca; Bota-Rabassedasa Neus; Jaumot i Pijoan, Montserrat; Vilardell, Felip; Capellá, G. (Gabriel); Agell i Jané, Neus
Lu, Albert; Tebar Ramon, Francesc; Alvarez-Moya, Blanca; López Alcalá, Cristina; Calvo Ademuz, Maria; Enrich Bastús, Carles; Agell i Jané, Neus; Nakamura, Takeshi; Matsuda, Michiyuki; Bachs Valldeneu, Oriol
Barceló, C.; Etchin, J.; Mansour, M. R.; Sanda, T.; Ginesta, M. M.; Sanchez-Arévalo Lobo, V. J.; Real, FX.; Capellá, G. (Gabriel); Estanyol i Ullate, Josep Maria; Jaumot i Pijoan, Montserrat; Look, A. T.; Agell i Jané, Neus
Tebar Ramon, Francesc; Vilallonga Smith, Príam de; Sorkina, Tatiana; Agell i Jané, Neus; Sorkin, Alexander; Enrich Bastús, Carles
Costelli, Paola; García Martínez, Celia; Llovera i Tomàs, Marta; Carbó Carbó, Maria Neus; López-Soriano, Francisco J.; Agell i Jané, Neus; Tessitore, Luciana; Baccino, Francesco M.; Argilés Huguet, Josep Ma.