1 / 11

G-Protein Coupled Receptors

G-Protein Coupled Receptors. Cell Biology. Introduction to G-Protein Coupled Receptors (GPCRs). Largest family of cell surface receptors More than 700 GPCRs in humans; mice have 1,000 that are involved in the sense of smell alone

dallon
Download Presentation

G-Protein Coupled Receptors

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. G-Protein Coupled Receptors Cell Biology

  2. Introduction to G-Protein Coupled Receptors (GPCRs) Largest family of cell surface receptors More than 700 GPCRs in humans; mice have 1,000 that are involved in the sense of smell alone Mediate responses to a number of signal molecules including neurotransmitters, hormones, local mediators and drugs (heroine, caffeine, histamine, etc.) About half of all known drugs work through GPCRs The 2012 Nobel Prize was awarded to a team who worked on GPCRs and their structure

  3. Cell Responses via GPCRs

  4. GPCR Structure Family of proteins that share similar structural and functional domains GPCR has 7 α helices that transverse the cellular membrane. Bacteria have similar membrane proteins but they don’t use G proteins

  5. G-Protein Structure Hetero trimeric protein (α,β and γ) GDP is bound to the α subunit when inactive; GTP is bound when α subunit is activate; βγ subunit is activated when α is activated The βγ subunit may or may not leave the α subunit Each G-Protein can affect different enzymes and/or ion channels May or may not be bound to GPCR

  6. cAMP Pathway can activate enzymes and turn on gene expressions. http://www.youtube.com/watch?v=vlEOgr7cbNY&feature=youtu.be

  7. Applications Cholera works by inhibiting the hydrolysis of GTP in the α subunit, thus maintaining the α subunit in its active state. The targeted response in the intestine is the outflow of Cl- and water, leading to severe dehydration and possibly death. Pertussis (whooping cough) alters the α subunit thereby disabling the G-protein and locking it into its inactive state. This leads to a prolonged signal which stimulates coughing.

  8. Applications (continued) • Caffeine inhibits cAMPphosphodiesterase, which breaks cAMPdown to AMP. If cAMP isn’t broken down then the cell stays active and this is how caffeine acts as a stimulant

  9. Applications (continued) • Overexpression of GPCRs contributes to cancer cell proliferation.

  10. Cited References • Alberts, B., Bray, D. Hopkin, K., Johnson, A., Lewis, J., Raff, M., Roberts, K. (2010). Essential Cell biology. New York, NY: Garland Science • Dorsam, Robert T., Gutkind, J. S., (2007) G-Protein Coupled Receptors and Cancer. Nature. 7(2), 79-94. http://www.nature.com/nrc/journal/v7/n2/fig_tab/nrc2069_T1.html

More Related