T2 cells also express BAFF-R, the receptor for the B-cell survival factor BAFF, whose expression is dependent on signals received through the BCR.

As B cells differentiate from the transitional T2 state to full maturity, they raise their levels of mIgD still further, while reducing the expression of mIgM. They also cease to express CD24 and CD93.

TLS Online TPP Program

#Id: 1343

#Unit 4. Cell Communication and Cell Signaling

RAS is a small monomeric G-proteins.

TLS Online TPP Program

#Id: 1344

#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.