K-Ras4B phosphorylation at Ser181 is inhibited by calmodulin and modulates K-Ras activity and function

Alvarez-Moya, Blanca; López-Alcalá, Cristina; Drosten, Matthias; Bachs, Oriol; Agell, Neus

doi:10.1038/onc.2010.298

Cited by 67 publications

(86 citation statements)

References 42 publications

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“…67 We previously reported a role of PKC-induced KRAS Ser181 phosphorylation for activation of the wild-type KRAS and regulation of oncogenic KRAS activity. In our model of NIH 3T3 transformed by oncogenic KRAS, the non-phosphorylatable KRAS significantly reduced its growth (P<0.0001) and failed to activate AKT at serum-limiting conditions but not at serum-saturating conditions, 52 suggesting that the role of KRAS phosphorylation was more prominent under serum starvation. Moreover we recently found that, when phosphorylation of KRAS was prevented, it did neither interact with PI3K (p110α) nor form clusters with PI3K.…”

Section: Discussionmentioning

confidence: 91%

“…[52][53][54] HeLa cells were transfected with the oncogenic KRAS phosphomutants for Ser181 phosphorylation ("phosphorylatable" wild-type (S), non-phosphorylatable (A) or phosphomimetic (D)) and cell lysates were immunoprecipitated with anti-HA antibody. We found that HNRNPA2B1 interacted with the "phosphorylatable" (S) and exhibited an enhanced interaction with the phosphomimetic (D), while no interaction was seen with the non-phosphorylatable (A) KRAS phosphomutant ( Fig 6A).…”

Section: Hnrnpa2b1 Interaction With Kras Depends On Kras Ser181-phospmentioning

confidence: 99%

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Ribonucleoprotein HNRNPA2B1 Interacts With and Regulates Oncogenic KRAS in Pancreatic Ductal Adenocarcinoma Cells

et al. 2014

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Section: Discussionmentioning

confidence: 91%

Section: Hnrnpa2b1 Interaction With Kras Depends On Kras Ser181-phospmentioning

confidence: 99%

Ribonucleoprotein HNRNPA2B1 Interacts With and Regulates Oncogenic KRAS in Pancreatic Ductal Adenocarcinoma Cells

et al. 2014

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“…BIM) (Alvarez-Moya et al, 2010). To conclusively demonstrate that Ser181 phosphorylation regulates the localization of oncogenic K-Ras in different nanoclusters at the plasma membrane, co-clustering of K-RasG12V-S181 with K-RasG12V-S181D and with K-RasG12V-S181A was analyzed after phosphorylation was induced (using PMA+W13) or phosphorylation was inhibited (using BIM) by using the immuno-EM-statistics approach indicated above (see Materials and Methods) (Fig.…”

Section: Resultsmentioning

confidence: 99%

“…Growth without contact inhibition, mobility and apoptosis resistance upon adriamycin treatment of cells that express oncogenic non-phosphorylatable K-Ras were highly compromised, correlating with decreased activation of the main downstream effectors ERK and AKT. Therefore, in our model, phosphorylation of K-Ras is essential to ensure the correct activation of ERK and AKT signaling pathways with an important functional relevance (Alvarez-Moya et al, 2010;Alvarez-Moya et al, 2011).…”

Section: Introductionmentioning

confidence: 99%

Oncogenic K-Ras segregates at spatially distinct plasma membrane signaling platforms according to its phosphorylation status

Barceló

Paco

Beckett

et al. 2013

Journal of Cell Science

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SummaryActivating 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 p110a, 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 KRas mutant, whereas (when PKC is inhibited) non-phosphorylated oncogenic K-Ras clusters with the non-phosphorylatable K-Ras mutant. Most interestingly, PI 3-kinase (p110a) 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.

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“…40,102,107 On the other hand, Agell et al identified PKCmediated and calmodulin (CaM)-dependent phosphorylation of K-Ras to modulate K-Ras activity and function. 108,109 In these studies, it was proposed that microdomains of nonphosphorylated K-Ras would be more accessible to p120GAP, consequently followed by K-Ras inactivation, whereas segregation of phosphorylated K-Ras into other microdomains would recruit a different set of effectors. Hence, interplay of RACK1, AnxA6, and CaM might coordinate the involvement of PKCα in the regulation of p120GAP localization and activity for H-and K-Ras.…”

Section: Nf1mentioning

confidence: 99%

Differential Regulation of RasGAPs in Cancer

et al. 2011

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Ever since their discovery as cellular counterparts of viral oncogenes more than 25 years ago, much progress has been made in understanding the complex networks of signal transduction pathways activated by oncogenic Ras mutations in human cancers. The activity of Ras is regulated by nucleotide exchange factors (GEFs) and GTPase activating proteins (GAPs), and much emphasis has been put into the biochemical and structural analysis of the Ras/GAP complex. The mechanisms by which GAPs catalyze Ras-GTP hydrolysis have been clarified and revealed that oncogenic Ras mutations confer resistance to GAPs and remain constitutively active. However, it is yet unclear how cells coordinate the large and divergent GAP protein family to promote Ras inactivation and ensure a certain biological response. Different domain arrangements in GAPs to create differential protein-protein and protein-lipid interactions are probably key factors determining the inactivation of the 3 Ras isoforms H-, K-, and N-Ras and their effector pathways. In recent years, in vitro as well as cell-and animal-based studies examining GAP activity, localization, interaction partners, and expression profiles have provided further insights into Ras inactivation and revealed characteristics of several GAPs to exert specific and distinct functions. This review aims to summarize knowledge on the cell biology of RasGAP proteins that potentially contributes to differential regulation of spatiotemporal Ras signaling.

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K-Ras4B phosphorylation at Ser181 is inhibited by calmodulin and modulates K-Ras activity and function

Cited by 67 publications

References 42 publications

Ribonucleoprotein HNRNPA2B1 Interacts With and Regulates Oncogenic KRAS in Pancreatic Ductal Adenocarcinoma Cells

Ribonucleoprotein HNRNPA2B1 Interacts With and Regulates Oncogenic KRAS in Pancreatic Ductal Adenocarcinoma Cells

Oncogenic K-Ras segregates at spatially distinct plasma membrane signaling platforms according to its phosphorylation status

Differential Regulation of RasGAPs in Cancer

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