In the absence of gibberellin, the DELLA proteins positively regulate GID1, GA20ox, and GA3ox (plus signs), and negatively regulate GA2ox (minus sign). Conversely, both bioactive gibberellin and the GID1 receptor enhance DELLA repressor degradation (plus signs), while GA2ox blocks DELLA repressor degradation (minus signs).

TLS Online TPP Program

#Id: 1335

#Unit 4. Cell Communication and Cell Signaling

The bacterial toxins that cause cholera and pertussis are enzymes that catalyze transfer of the ADP ribose moiety.

TLS Online TPP Program

#Id: 1336

#Unit 4. Cell Communication and Cell Signaling

RTK ligands- NGF, PDGF, FGF, EGF

TLS Online TPP Program

#Id: 1337

#Unit 4. Cell Communication and Cell Signaling

All RTKs have a cytosolic domain with protein tyrosine kinase activity

TLS Online TPP Program

#Id: 1338

#Unit 4. Cell Communication and Cell Signaling

The EGFR specifically binds EGF in a lock-and-key type of mechanism.

TLS Online TPP Program

#Id: 1339

#Unit 4. Cell Communication and Cell Signaling

The function of a growth factor-  stabilize receptor dimerization

TLS Online TPP Program

#Id: 1340

#Unit 4. Cell Communication and Cell Signaling

HER1 & HER4, can form stable homodimers after binding a growth factor.