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#Ras

3 public questions tagged with this topic.

Cancer

Loss of p53 cooperates with Ras by

The tumor-suppressor protein p53 is kept at low levels in unstressed cells by continuous MDM2-mediated ubiquitination and degradation. DNA damage or oncogenic stress leads to phosphorylation of p53 or induction of ARF, both of which block the p53–MDM2 interaction. Stabilized p53 then transcriptionally activates genes that induce cell-cycle arrest, DNA repair or apoptosis, thereby preventing propagation of damaged genomes.

Ref: NCERT Biology Class 11–12 Alberts et al Molecular Biology of the Cell Lodish et al, Molecular Cell Biology Cooper & Hausman, The Cell Abbas et al., Cellular and Molecular Immunology (for immunology sections)

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Cancer

Ras and Myc cooperate in cancer by

Full malignant transformation usually requires the cooperative action of multiple oncogenes and the loss of tumor suppressors. A single oncogene is rarely sufficient because cells possess multiple barriers—apoptosis, senescence, DNA-damage checkpoints—that must be overcome. Classic experiments demonstrated that Ras and Myc together bypass these barriers more effectively than either alone, illustrating the multi-hit nature of carcinogenesis.

Ref: NCERT Biology Class 11–12 Alberts et al Molecular Biology of the Cell Lodish et al, Molecular Cell Biology Cooper & Hausman, The Cell Abbas et al., Cellular and Molecular Immunology (for immunology sections)

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Cell Signaling ELR Pathways - I

Ras directly activates which downstream protein?

Raf, is consistent with established principles of cell signaling, receptor pharmacology and cellular regulation. Experimental measurements of binding parameters, genetic loss-of-function studies and pharmacological interventions all converge on the same interpretation. Related options address neighboring concepts but do not satisfy the precise criterion stated in the question.

Ref: NCERT Biology Class 11–12 Alberts et al Molecular Biology of the Cell Lodish et al, Molecular Cell Biology Cooper & Hausman, The Cell Abbas et al., Cellular and Molecular Immunology (for immunology sections)

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