Membrane_receptor_systems

Membrane_receptor_systems - - NOT ON MIDTERM 1 - has to do...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Topic 5 – Cell-to-cell signalling Reading Chapter 8 Objectives Cell communication and signalling systems BIO 1140 – SLIDE 1 Signals recognized by cell- surface receptors Ligand-gated channels Receptor tyrosine kinases G protein-coupled receptors Lipid-soluble signals & intracellular receptors http:/ www.cel signal.com/reference/pathway/ Types of cell communication Direct – gap junctions and plasmodesmata Contact – recognition and adhesion e.g. cadherins, integrins Chemical messengers Cel A Cell communication – the broader context BIO 1140 – SLIDE 2 Cel B pore connexin connexon smal molecule http:/ www.ncbi.nlm.nih.gov/books/NBK9874/ http:/ www.ncbi.nlm.nih.gov/books/NBK9834/ cadherins Types of chemical messengers Hormones Paracrine messengers Neurotransmitters and neurohormones BIO 1140 – SLIDE 3 Fig. 16-3, Alberts et al. 2010 - NOT ON MIDTERM 1 - has to do mostly with multicellular organisms - greatest need for cells to communicate with each other - can be very complex - despite this, basic principles exist for signalling - two broad signalling - how they enter cell differs - cell to cell communication occurs in a variet of ways direct - ex. coordinating heart beat with gap junctions contact -cell surface proteins that either bind to each other or to other molecules chemical messengers - many types - hormones - chemical messengers synthesized by specialized cells --- transported by vesicles to distant destination - neurotransmitters - in neurons - paracrine - secreted by a cell that act on other cells -- local mediator is a paracrine messenger Pop quiz - distinguish between Ras and G-protein -- G protein - made up of three subunits while Ras is a type of G-protein that is only one subunit. -- both hydrolyze GTP -- Ras involved in cell growth and differentiation - often have growth factors - receptor kinase. .. -- G protein - heterotrimeric proteins activated by G-protein coupled receptors - adenylyl cyclase and why does it matter? -- enzyme that produces GNP activated by G-protein - adenylyl cyclase is how we get cAMP - everyone wants that - caffeine (phosphodiesterase inhibitor) be predicted to have on glucose release from liver cells? -- increase glucose release from liver cells by increasing glycogen breakdown - phosphodiesterase stops formation of cAMP - this prevents phosphodiesterase from binding- prolonged effect of cAMP
Background image of page 1

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

View Full DocumentRight Arrow Icon
The “fight or flight” response What is this response? How is it activated? BIO 1140 – SLIDE 4 Steps in a signalling system Signalling molecule (first messenger) Reception Ligand-binding site Only cells with receptor respond to signal Membrane, cytosolic or nuclear BIO 1140 – SLIDE 5 Transduction Conversion of signal to cellular response Cellular response Changes in gene expression Changes in protein activity Responses can be cell type-specific
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 9

Membrane_receptor_systems - - NOT ON MIDTERM 1 - has to do...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online