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KRAS proto-oncogene, GTPase

The KRAS gene provides instructions for making a protein called K-Ras that is part of a signaling pathway known as the RAS/MAPK pathway. The protein relays signals from outside the cell to the cell's nucleus. These signals instruct the cell to grow and divide (proliferate) or to mature and take on specialized functions (differentiate). The K-Ras protein is a GTPase, which means it converts a molecule called GTP into another molecule called GDP. In this way the K-Ras protein acts like a switch that is turned on and off by the GTP and GDP molecules. To transmit signals, it must be turned on by attaching (binding) to a molecule of GTP. The K-Ras protein is turned off (inactivated) when it converts the GTP to GDP. When the protein is bound to GDP, it does not relay signals to the cell's nucleus.

Normal function

The KRAS gene provides instructions for making a protein called K-Ras that is part of a signaling pathway known as the RAS/MAPK pathway. The protein relays signals from outside the cell to the cell's nucleus. These signals instruct the cell to grow and divide (proliferate) or to mature and take on specialized functions (differentiate). The K-Ras protein is a GTPase, which means it converts a molecule called GTP into another molecule called GDP. In this way the K-Ras protein acts like a switch that is turned on and off by the GTP and GDP molecules. To transmit signals, it must be turned on by attaching (binding) to a molecule of GTP. The K-Ras protein is turned off (inactivated) when it converts the GTP to GDP. When the protein is bound to GDP, it does not relay signals to the cell's nucleus.

The KRAS gene belongs to a class of genes known as oncogenes. When mutated, oncogenes have the potential to cause normal cells to become cancerous. The KRAS gene is in the Ras family of oncogenes, which also includes two other genes: HRAS and NRAS. These proteins play important roles in cell division, cell differentiation, and the self-destruction of cells (apoptosis).

Conditions referring to this gene or chromosome

Other names

C-K-RAS

c-K-ras protein

c-K-ras2 protein

c-Kirsten-ras protein

cellular c-Ki-ras2 proto-oncogene

K-ras p21 protein

KI-RAS

Kirsten rat sarcoma viral oncogene homolog

KRAS1

PR310 c-K-ras oncogene

RASK2

RASK_HUMAN

transforming protein p21

v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog

Further reading and references

Article history

The information on this page is written and peer reviewed by qualified clinicians.
  • 12 Apr 2023 | Latest version
  • 1 Dec 2017 | Originally published

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