Ras Subfamily
Ras Subfamily - Related Videos
02:38
The Ras Gene
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2021
The Ras-gene-encoded proteins are regulators of signaling pathways controlling cell proliferation, differentiation, or cell survival. The Ras-gene family in humans constitutes three primary members—the HRas, NRas, and KRas. These genes code for four functionally distinct yet closely related proteins—the HRas, NRas, KRas4A, and KRas4B. The involvement of mutant Ras genes in human cancer was first discovered in 1982 and is among the most common causes of human tumorigenesis. Ras is a superfamily...
02:38
The Ras Gene
0 Views •
2023
The Ras-gene-encoded proteins are regulators of signaling pathways controlling cell proliferation, differentiation, or cell survival. The Ras-gene family in humans constitutes three primary members—the HRas, NRas, and KRas. These genes code for four functionally distinct yet closely related proteins—the HRas, NRas, KRas4A, and KRas4B. The involvement of mutant Ras genes in human cancer was first discovered in 1982 and is among the most common causes of human tumorigenesis. Ras is a superfamily...
01:24
Small GTPases - Ras and Rho
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2023
Ras and Rho are small monomeric GTPases that act downstream of receptor tyrosine kinase (RTK) and regulate various cellular processes. These GTPases switch between active and inactive states by binding to guanine nucleotides. Three regulatory proteins control their activity: Guanine nucleotide exchange factors or GEF, GTPase-activating proteins or GAPs, and Guanine nucleotide-dissociation inhibitors or GDIs. The GEF activates the GTPase by exchanging the bound-GDP with GTP. The GTPases’...
08:12
Identification of EGFR and RAS Inhibitors using Caenorhabditis elegans
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Cited by 4 •
2020
The genetically tractable nematode Caenorhabditis elegans can be used as a simple and inexpensive model for drug discovery. Described here is a protocol to identify anticancer therapeutics that inhibit the downstream signaling of RAS and EGFR proteins.
02:57
piRNA - Piwi-interacting RNAs
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2020
PIWI-interacting RNAs, or piRNAs, are the most abundant short non-coding RNAs. More than 20,000 genes have been found in humans that code for piRNAs while only 2000 genes have been found for miRNAs. piRNAs can act at the transcriptional and post-transcriptional levels and have a vital role in silencing transposable elements present in germ cells. They are also involved in epigenetic silencing and activation. Previously, they were thought to function only in germ cells but new evidence suggests...
FAQs
Ras signaling depends on the controlled replacement of GDP with GTP and the subsequent return to the GDP-bound state. Guanine nucleotide exchange factors promote the activation step, whereas GTPase-activating proteins accelerate GTP hydrolysis. The balance between these opposing activities determines how long Ras remains signaling-competent and therefore influences the strength and duration of downstream cellular responses.
These regulatory proteins provide complementary control over the Ras cycle. Exchange factors increase the formation of active, GTP-bound Ras, while activating proteins speed its conversion back to the inactive GDP-bound form. Their opposing effects prevent signaling from being governed solely by activation and allow cells to adjust Ras output as extracellular cues change.
Membrane association positions Ras within the cellular signaling environment where extracellular information is relayed to intracellular pathways. From this location, active Ras can engage downstream effectors, including protein kinases. This spatial organization helps connect nucleotide-state changes to signaling events that alter proliferation, differentiation, survival, and gene expression.
Activating mutations can shift Ras signaling toward persistent activity rather than a normally regulated pattern of activation and termination. Continued engagement of downstream effectors may maintain signals that influence proliferation, survival, and gene expression. This abnormal persistence provides a mechanistic link between altered Ras regulation and the development of cancer-related cellular behavior.
Examining the cycle reveals how an extracellular cue can produce a controlled intracellular response. Researchers can relate the balance of GDP-bound and GTP-bound Ras to effector engagement, signal duration, and changes in cell behavior. This framework helps distinguish regulated signaling involved in normal biology from persistent signaling associated with activating mutations.
Ras proteins are important because activating mutations can produce persistent downstream signaling, a feature relevant to cancer biology. Studying the nucleotide cycle, regulatory proteins, and effector pathways helps researchers connect molecular alterations with changes in cell behavior. That mechanistic understanding supports efforts to investigate therapeutic strategies directed at abnormal signaling.
Ras links signals received outside the cell to intracellular changes that influence proliferation, differentiation, survival, and gene expression. Those responses are relevant to normal tissue development because cells must alter their behavior in response to signaling cues. Comparing regulated developmental signaling with mutation-driven persistence helps clarify how similar pathways can support normal or abnormal outcomes.