Intercellular and intracellular cell signaling pathway

signaling pathway

1. M pharmacy 1 st sem. Session :- 2020-2021 TOPIC :- Intercellular and intracellular signaling pathway Subject code :- MPL 103T Subject name :- Cellular and Molecular Pharmacology Submitted By :- Sachin Gulia (9003) Submitted To :- Anuradha ma’am MAHARSHI DYANAND UNIVERSITY

2. CELL SIGNALING PATHWAYS A biological mechanism that occurs in cells which gives cells an ability to receive or generate the signals in response to their surrounding environment. Communication between or within the cells. RECEIVING TRANSDUCTION RESPONSE STAGES OF CELL SIGNALING

3. CELL SIGNALING PATHWAYS Intercellular cell signaling pathway Or Intracellular cell signaling pathway

4. INTERCELLULAR SIGNALING Intercellular signals can travel all throughout the body. This allows certain glands within the body to produce signals which take action on many different tissues across the body . Communication between cells.

5. TYPES OF INTERCELLULAR SIGNALING PATHWAYS Autocrine signaling Paracrine signaling Endocrine signaling Juxtacrine signaling

6. AUTOCRINE SIGNALING PATHWAY Cells send signals to themselves. Cell secretes signals molecules that can bind back to its own receptors. Important during embryonic development. Examples :- Tumor cells, cancer cells etc

7. PARACRINE SIGNALING PATHWAY Paracrine signaling depends on local mediators that are released into the extracellular space and act on neighboring cells. This type of signaling in which cells communicate over relatively sort distances, is know as paracrine signaling. Neurotransmitters represent an example .

8. ENDOCRINE SIGNALING PATHWAY This is type of communication occurring between distant cells and mediated by hormones. The hormones are released by endocrine cells of the body. Signaling molecules (hormones) travel through the blood and act upon particular target cells. The cause slow but long lasting response .

9. JUXTRACRINE SIGNALING PATHWAY When signal molecule remains bound to the cell that produced it and therefore, will only influence cells that directly contact it, then this type of intercelluar signaling is know as contact dependent signaling. This type of signaling is very important in the development of multicellular organism and in the immune system.

10. INTRACELLULAR SIGNALING PATHWAYS The chain of molecules that relay inside a cell are known as intracellular signaling pathways . When a ligand binds to a cell-surface receptor , the receptor’s intracellular domain changes in some way.

11. STEPS IN INTRACELLULAR SIGNALING PATHWAY Synthesis of extracellular signal molecule. Release of signaling molecule by the signaling cell. Transport of the signal to the target cell. Detection of the signal by a specific receptor protein. A change in cellular metabolism, function or development triggered by the receptor-signal complex. Removal of the signal, which often terminates the cellular response.

12. TYPE OF INTRACELLULAR SIGNALING PATHWAYS G – protein coupled receptor Enzyme-linked receptor Ligand-gated ion channels Second messenger signaling pathways Cyclic AMP pathway MAPK signaling The JAK/STAT signaling pathway

13. G – protein coupled receptor Serpentine receptor 7- pass receptor Ligand binding domain – effector domain 3 sub-units :- alpha, beta, gamma Alpha bind with GDP(guanosine diphosphate) and GTP The N- terminus of the protein is exposed to the extracellular fluid, while the C- terminus resides in the cytosol .

14. Enzyme-linked receptor Catalytic receptor One pass receptor Single transmembrane helix. Activation – growth factor, cytokines, hormones Effect – gene transcription Events – cell growth and differentiation

15. Ligand-gated ion channels Open in response to specific ligand molecules binding to the extracellular domain of the receptor protein . Passive mechanism . Two domains Extracellularly activated ligand-gated ion channel . ( nicotinic receptors, GABA (a and c) serotonin) intracellularly activated ligand-gated ion channel (Ca activated potassium pump , chloride pump , ATP sensitive potassium pump)

16. Cyclic AMP pathway (second messenger signaling) Adenylyl cyclase pathway Mechanism :- signal molecule bind to surface receptor. Surface receptor activates a G- protein. G- protein activates to membrane bound enzyme, adenylyl cyclase. Adenylyl cyclase catalyzes synthesis of cAMP , Which bind to a target protein. Target protein initiates cellular change.