Dosage compensation

Equalization in males and females of the amount of protein produced by X-linked genes.

Each female cell one of the two X chromosome becomes inactive. Which X chromosome is inactivated is random.

The Xist (X inactive specific transcript) gene located on the X chromosome, in required for inactivation. 

TLS Online TPP Program

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#Unit 4. Cell Communication and Cell Signaling

RAS is connected to the membrane by a prenylated (lipid) tail.

TLS Online TPP Program

#Id: 1345

#Unit 4. Cell Communication and Cell Signaling

All Ras have the CAAX motifs at the C-terminus.

TLS Online TPP Program

#Id: 1346

#Unit 4. Cell Communication and Cell Signaling

Post-translational modifications of the CAAX motifs determine the subcellular localization and correct biological function of Ras proteins.

TLS Online TPP Program

#Id: 1347

#Unit 4. Cell Communication and Cell Signaling

SOS – Ras GEF

NF1 - Ras GAP

TLS Online TPP Program

#Id: 1348

#Unit 4. Cell Communication and Cell Signaling

RasD or RasONC  Replacement of the normal glycine 12 with any other amino acid (except proline) “locks” Ras in the active GTP-bound state.

TLS Online TPP Program

#Id: 1349

#Unit 4. Cell Communication and Cell Signaling

RAF (also known as MAPKKK),  A ser/thr protein kinase