Types of signaling

cell signaling mechanism

1. TYPES OF CELL SIGNALING (with specific example of each) PRESENTED BY- NEHA MAYACH M.Sc. LIFE SCIENCES (3 rd semester) CENTRAL UNIVERSITY OF GUJARAT DATE- 11.08.2015

2. CONTENT Introduction of cell signaling Its need Brief history Types of cell signaling- Autocrine Paracrine Endocrine Recapitulation Review article using types of cell signaling Reference

3. CELL SIGNALLING- (Brief H istory) In 1970, Martin Rodbell   examined effects of  glucagon   on rat's liver cell membrane receptor . He revealed about guanosine triphosphate   and stimulated G-protein role in cell's metabolism .

4. AUTOCRINE cells respond to substances which they themselves release and thus changes takes place in the cell itself

5. EXAMPLE:- Tumour cells release growth factors for their own survival and proliferation

6. ENDOCRINE Signaling over long distance Signal molecules(hormones) secreted by glands Bloodstream carries hormones far and wide may lie anywhere in the body

7. EXAMPLE:- Epinephrine - amino acid derivative(of tyrosine) hydrophilic signaling molecule (bind to G protein coupled receptor) Released from Adrenal medulla

8. FUNCTION- Glycogen breakdown Gluconeogenesis (glucose from pyruvate)

9. Glycogen breakdown Glycolysis(more ATP) Beta Oxidation (breakdown of fatty acid for energy) Acts on MUSCLE cells to make ATP-

10. FIGHT OR FLIGHT (The physiological response to a threatening situation, which readies one either to resist forcibly or to run away ) Muscle needs energy! So liver makes glucose and muscle breaks glucose down to ATP. Available for use to fight and flight.

11. 7TM receptor(serpentine receptor) Made up of single polypeptide

12. PARACRINE S ignaling molecules released by a secretory cell affect only those target cells in close proximity

13. For paracrine signals to act locally , secreted molecules must not be allowed to diffuse to far. Rapidly taken up by neighboring target cells or immobilized by ECM.

14. EXAMPLES:- conduction by a neurotransmitter of a signal from one nerve cell to another or from a nerve cell to a muscle cell Mostly studies neurotransmitters-

15. NEURO-MUSCULAR JUNCTION

16. Chemically gated receptors or Ion channel receptors

17. ION GATED CHANNEL Fundamental task of neuron-to receive, conduct, transmit signals. Neurons are excitable cells, have ability to respond to stimulus by producing an electrical signal. Nerve impulse propagates at speed ranging from 0.5 to 130 ms.

18. REVIEW ARTICLE Autocrine insulin-like growth factor-I signaling promotes growth survival of human acute myeloid leukemia cells via the phosphoinositide 3-kinase/ Akt pathway role for autocrine IGF-I signaling in the growth and survival of primary AML cells. IGF-IR inhibitors in combination with chemotherapeutic agents may represent a novel approach to target human AML(Acute myeloid leukemia)

19. RECAPITULATE AUTOCRINE CELL SIGNALING- normal cell ,cancer cell ENDOCRINE CELL SIGNALING- epinephrine, GPCR, G protein, adenylate cyclase, cAMP fight and flight response PARACRINE CELL SIGNALING- Neurotransmitter, neuro-muscular transmitter, ion gated channels

20. REFERENCES:- THE CELL- Geoffrey M.Cooper and Robert E.Hausman (5 th edition) BIOCHEMISTRY- Lubert Stryer (6 th edition) THE CELL- Alberts (5 th edition) Review(Nature) Leukemia (2007) Nature Publishing Group www.nature.com/leu

21. THANK YOU