02-Cell Signalling

02-Cell Signalling - I ImportanceandBasics II. locallyorata...

Info iconThis preview shows pages 1–8. Sign up to view the full content.

View Full Document Right Arrow Icon
Cell Signals and Signal Transduction I.   Importance and Basics II.   Signals regulate protein function and may act           locally or at a  distance III. Two Classes of Signal Molecules      Membrane Permeable – Intracellular Receptors      Membrane Impermeable – Membrane Receptors IV.  Three Steps      Reception   Transduction    Response V.    Reception      Ligand (signal) binds to receptor protein VI.  Transduction Mechanisms  and Responses      Intracellular Receptors      Receptors Coupled to Ion Channels      G-protein Coupled Receptors      Receptor Tyrosine Kinases
Background image of page 1

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

View Full DocumentRight Arrow Icon
Signals: What do they do? Signals exert effects by directly or indirectly regulating  protein   function in target  c e lls        Pro te in Func tio n is  la rg e ly de te rm ine d by s ha pe       S o , pro te in func tio n c a n be  re g ulate d b y m o difying  the  pro te in’s  s ha pe   (c a us ing  a  c o nfo rm a tio na l c ha ng e ) whic h a lte rs  the  pro te in’s  a bility  to  func tio n . Pro te ins  c a n b e  ac tiva te d o r ina c tivate d b y  c o nfo rm a tio nal c ha ng e s .
Background image of page 2
Regulating a Protein’s Shape The two major mechanisms are: A) A llosteric regulation -  regulation of  a  pro te in b y b inding  o f a n e ffe c to r  m o le c ule  a t the  pro te in's  a llo s te ric  s ite   B)  Covalent modification – e .g .,  pho s pho ryla tio n o f o ne  o f the  a m ino   a c ids   in the  pro te in (s e rine ,thre o nine , o r  tyro s ine ) How does the signal get from the Signaling Cell to the Target Cell ?
Background image of page 3

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

View Full DocumentRight Arrow Icon
In Some Cases Signaling Occurs via Cell-Cell Contact Gap junctions and plasmodesmata  allow for the direct transfer of ions  or small molecules from one cell to  another.  Cell to cell contacts can allow signals  attached to the surface of one cell to  interact with receptors attached to  the surface of an adjacent cell  triggering a response. These pathways  are particularly important in  development.
Background image of page 4
More Common: Signals are Carried by  Secreted  Signal Molecules Signals released from one cell may travel to a target cell and act on receptors located on  the surface of or within the cytoplasm of the target cell
Background image of page 5

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

View Full DocumentRight Arrow Icon
There are three general steps that are common to cell signaling  pathways Reception   ( A signal molecule binds to a receptor in the  membrane or cytoplasm of the target cell) Transduction   (The receptor activates relay molecules) Response   (The relay molecules act on an effector molecule  that  drives the response)  
Background image of page 6
There Are Two General Classes of Secreted Signal  Molecules 1. Signals that are membrane permeable (steroid hormones, thyroid hormones)
Background image of page 7

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

View Full DocumentRight Arrow Icon
Image of page 8
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 31

02-Cell Signalling - I ImportanceandBasics II. locallyorata...

This preview shows document pages 1 - 8. Sign up to view the full document.

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