This entails release of DnaC, which allows the DnaB helicase to become active. DnaC hydrolyzes ATP in order to release DnaB. This step marks the transition from initiation to elongation.

TLS Online TPP Program

#Id: 9649

#Unit 4. Cell Communication and Cell Signaling

In humans, there are three RAS, three Raf, two MEK, and two MAP proteins.

TLS Online TPP Program

#Id: 9650

#Unit 4. Cell Communication and Cell Signaling

Mammalian MAP kinases include  Jun N-terminal kinases and p38 kinases, which are activated by signaling pathways in response to various types of stresses

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#Id: 9651

#Unit 4. Cell Communication and Cell Signaling

Phosphorylation by MEK at Y-185 and T-183 in activation loop of MAP kinase leads to a marked conformational change & promotes MAP kinase activation and dimerization.

TLS Online TPP Program

#Id: 9652

#Unit 4. Cell Communication and Cell Signaling

TLS Online TPP Program

#Id: 9653

#Unit 4. Cell Communication and Cell Signaling

Activated dimeric MAP kinase induces transcription of the c-fos gene by directly activating TCF, and indirectly activating SRF.

TLS Online TPP Program

#Id: 9654

#Unit 4. Cell Communication and Cell Signaling

Feedback regulation by MAP Kinase

activated MAP kinase phosphorylates the HER1 on a threonine residue near the juxtamembrane domain.