Tranduction Regulation of Transcription

14 grb2 protein also contains an sh3 domain which

Info icon This preview shows pages 14–24. Sign up to view the full content.

View Full Document Right Arrow Icon
14
Image of page 14

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Grb2 protein also contains an SH3 domain, which binds proline-rich domains in proteins like Sos Sos is a GEF for Ras Ras is monomeric G-protein tethered to plasma membrane by lipid tail Localized binding of Grb2-Sos puts Ras-GEF (Sos) in close proximity to Ras-GDP Recruitment of adaptor molecules to phosphorylated RTK 15
Image of page 15
Sos binding to Ras-GDP induces GDP-GTP exchange Ras-GTP is active form Binds to and activates downstream effectors at the plasma membrane GEF activates Ras 16
Image of page 16

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Active Ras Triggers Kinase/Phosphorylation Sequence MAP- Mitogen Activated Protein/ Microtubule-Associated Protein 17
Image of page 17
Active MAPK enters nucleus Phosphorylates Transcription factors TF bind to specific response elements in target genes Increases transcription of specific genes Active MAPK enters nucleus and phosphorylates target transcription factors 18
Image of page 18

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Normal setting Sevenless receptor is expressed in receiving cell Bride-of-seveless ligand is expressed in signaling cell Binding of Boss to Sev induces signal transduction that results in fate decision = R7 neuron Mutant setting Loss of Sev Receptor leads to change in fate decision = cone cell Genetics to define signal transduction pathway 19
Image of page 19
Mutant setting Loss of Sev Receptor leads to change in fate decision = cone cell Rescue experiments Add molecules (mutant or overexpression of wild type molecules) in mutant cells and determine which ones restore the normal trait (R7 neuron) Epistasis analyses can reveal the order of signaling components Double mutant Analysis Activated Ras restores R7 neuron fate in sev mutant cells Ras is downstream of sev receptor 20
Image of page 20

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Regulated by protein cleavage or destruction 21
Image of page 21
22 Wnt Signaling Players Receptors - Frizzled (7-TM spanning) LRP Ligands- Wnts (lipid modified) Intracellular Effectors - Positive Regulators: Dishevelled Beta-catenin TCF (TF) Negative Regulators: Axin (Scaffold) APC (Adaptor) GSK3 (Kinase) TCF (TF) Wnt1 overexpressing breast cancer Wingless fly mutant
Image of page 22

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
No ligand Destruction complex binds to and targets beta-catenin for destruction Axin acts as scaffold for APC and GSK3 GSK3 phosphorylates beta-catenin
Image of page 23
Image of page 24
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern