Presentation on theme: "Chapter 11 Cell Communication. Overview: The Cellular Internet Cell-to-cell communication is essential for multicellular organisms Biologists have discovered."— Presentation transcript:
Fig. 11-5ab Local signaling Target cell Secretory vesicle Secreting cell Local regulator diffuses through extracellular fluid (a) Paracrine signaling (b) Synaptic signaling Target cell is stimulated Neurotransmitter diffuses across synapse Electrical signal along nerve cell triggers release of neurotransmitter
Fig. 11-7b G protein-coupled receptor Plasma membrane Enzyme G protein (inactive) GDP CYTOPLASM Activated enzyme GTP Cellular response GDP P i Activated receptor GDP GTP Signaling molecule Inactive enzyme 1 2 3 4
Fig. 11-7c Signaling molecule (ligand) Ligand-binding site Helix Tyrosines Tyr Receptor tyrosine kinase proteins CYTOPLASM Signaling molecule Tyr Dimer Activated relay proteins Tyr P P P P P P Cellular response 1 Cellular response 2 Inactive relay proteins Activated tyrosine kinase regions Fully activated receptor tyrosine kinase 6 6 ADP ATP Tyr P P P P P P 1 2 3 4
Fig. 11-9 Signaling molecule Receptor Activated relay molecule Inactive protein kinase 1 Active protein kinase 1 Inactive protein kinase 2 ATP ADP Active protein kinase 2 P P PP Inactive protein kinase 3 ATP ADP Active protein kinase 3 P P PP i ATP ADP P Active protein PP P i Inactive protein Cellular response Phosphorylation cascade i
Fig. 11-13-1 EXTRA- CELLULAR FLUID Signaling molecule (first messenger) G protein GTP G protein-coupled receptor Phospholipase C PIP 2 IP 3 DAG (second messenger) IP 3 -gated calcium channel Endoplasmic reticulum (ER) Ca 2+ CYTOSOL
Fig. 11-13-2 G protein EXTRA- CELLULAR FLUID Signaling molecule (first messenger) G protein-coupled receptor Phospholipase C PIP 2 DAG IP 3 (second messenger) IP 3 -gated calcium channel Endoplasmic reticulum (ER) Ca 2+ CYTOSOL Ca 2+ (second messenger) GTP
Fig. 11-13-3 G protein EXTRA- CELLULAR FLUID Signaling molecule (first messenger) G protein-coupled receptor Phospholipase C PIP 2 DAG IP 3 (second messenger) IP 3 -gated calcium channel Endoplasmic reticulum (ER) Ca 2+ CYTOSOL Various proteins activated Cellular responses Ca 2+ (second messenger) GTP
Fig. 11-14 Growth factor Receptor Phosphorylation cascade Reception Transduction Active transcription factor Response P Inactive transcription factor CYTOPLASM DNA NUCLEUS mRNA Gene
Fig. 11-15 Reception Transduction Response Binding of epinephrine to G protein-coupled receptor (1 molecule) Inactive G protein Active G protein (10 2 molecules) Inactive adenylyl cyclase Active adenylyl cyclase (10 2 ) ATP Cyclic AMP (10 4 ) Inactive protein kinase A Active protein kinase A (10 4 ) Inactive phosphorylase kinase Active phosphorylase kinase (10 5 ) Inactive glycogen phosphorylase Active glycogen phosphorylase (10 6 ) Glycogen Glucose-1-phosphate (10 8 molecules)
Jacobson et al (1997) Cell, Vol. 88, 347– 354, Apoptosis plays in an important role in normal developmental processes Studies on the development of the nervous system showed that in the process of assembling sensory fields, neurons are eliminated by orderly cell death in order to tailor sensory input to environmental stimuli (elimination or transplantation of limbs as key examples).
Programmed cell death during development. Programmed cell death is involved in forming structures such as the digits of the hand (a), deleting structures such as nearly all of an insect's larval components (b), controlling cell numbers in, for example, the nervous system (c) and eliminating abnormal cells such as those that harbour mutations (d).
Apoptosis is also important in the development of the nervous system