Difference between revisions of "Signal 1"

From CellBiology
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* "cell signaling"  [http://www.ncbi.nlm.nih.gov/sites/gquery?itool=toolbar&cmd=search&term=cell+signaling Entrez all databases]
* "cell signaling"  [http://www.ncbi.nlm.nih.gov/sites/gquery?itool=toolbar&cmd=search&term=cell+signaling Entrez all databases]
* "steroid signaling"  [http://www.ncbi.nlm.nih.gov/sites/gquery?itool=toolbar&cmd=search&term=steroid+signaling Entrez all databases]
* "steroid signaling"  [http://www.ncbi.nlm.nih.gov/sites/gquery?itool=toolbar&cmd=search&term=steroid+signaling Entrez all databases] | [http://www.ncbi.nlm.nih.gov/images?term=steroid%20signaling images]

Revision as of 09:00, 17 May 2011

ANAT3231 Cell Biology online lectures from the 2017 course.

Cell Signaling 1

This lecture is an introduction to a series of lectures on cell signaling. The first lecture is a general introduction to the different signaling mechanisms and the following two lectures look in detail at some specific examples of signaling pathways.

Note that you have already been introduced to signaling in many of your other lecture topics (searching PubMed for "cell signaling" gives 410,092 results).

2009 lecture 2008: ANAT3231 Lecture 18-19 Cell Signaling


Movie - Neutrophil chasing Bacterium


  • Understand main types of signaling mechanisms
  • Understand concept of receptor and ligand
  • Understand membrane, cytoplasmic and nuclear receptors
  • Brief understanding of steroid hormone pathway
  • Brief understanding protein growth factor pathway
  • Understand differences between select membrane receptors (G protein structure, tyrosine kinases)

Lecture Summary

  • Messengers and Receptors
  • chemical signals
  • cellular receptors
  • signal transduction
  • intracellular pathways
  • second messengers
  • Examples of signaling

Signaling Mechanisms

MCB Movie - Extracellular Signaling

  • Endocrine
    • Hormone (at a distance)
  • Paracrine
    • Locally
  • Neurotransmitter
    • Specific form of paracrine
  • Autocrine
  • Local (self)
  • Contact Dependent

Signal transduction pathways.png

Cell Communication

  • Contact Mediated
    • display molecules on cell surface
    • recognized by receptor on another cell
  • Non-Contact Mediated
    • chemical signal
    • nearby or at a distance

Common Signals Signals and Receptors Signal Transduction Model Signaling between Tissues Regulation of cells and tissues

Hormones secreted by one tissue to regulate function of other cells or tissues

Chemical Signal Types

  • water soluble
  • lipid soluble

Movie: Hormone Signaling

Extracellular Signal Steps

  • Signaling Molecule
  • Synthesis
  • Release by signaling cell
  • Transport to target cell
  • Detection by a specific receptor protein
  • Change by receptor-signal complex (trigger)

Cell Surface Receptors

  • four main classes
    • G protein–coupled receptors
    • ion-channel receptors
    • receptors linked to cytosolic tyrosine kinases
    • receptors with intrinsic catalytic activity
  • ligand binding to cell-surface receptor
    • trigger intracellular pathways
    • modulate cellular metabolism, function, or development
  • Removal of the signal
    • often terminates cellular response

Second Messengers

cAMP molecular structure
Cyclic guanosine monophosphate (cGMP)
  • Cyclic nucleotides
    • cAMP, cGMP
  • Calcium Ions
  • Protein Kinase A
    • PKA, B, C
  • diacylglycerol (DAG)
    • modified lipid activates PKC
  • regulate the activity of cellular proteins
    • enzymes and non-enzymatic

Links: Cell - Common intracellular signaling proteins Elevation of cytosolic Ca2+ via the inositol-lipid signaling pathway | View Movie: Second Messengers in Signaling Pathways

Steroid Responses

Steroid hormone receptor signaling


Cytosol location

  • receptor bound to inhibitor
  • ligand binding activates receptor
  • translocates to nucleus on ligand binding

Nuclear location

  • binds ligand and DNA
  • becomes transcription factor

MCB - Characteristic Properties of Principal Types of Mammalian Hormones | MCoB - Some signaling molecules that bind to nuclear receptors | Cell - Action of steroid hormones

Steroid Hormone Receptors (SHRs)

48 human nuclear receptor types

Steroid hormone receptor family
  • estrogen receptor, two forms ERα [NR3A1] and ERβ [NR3A2]
  • cortisol binding glucocorticoid receptor (GR) [NR3C1]
  • aldosterone binding mineralocorticoid receptor (MR) [NR3C2]
  • progesterone receptor (PR) [NR3C3]
  • dihydrotestosterone (DHT) binding androgen receptor (AR) [NR3C4]


Nuclear Receptor Signaling

Steroid Receptors

  • steroid binding region
  • near C-terminus
  • DNA binding
  • central region
  • zinc finger motif
  • alpha helix and 2 beta sheets held in place by cysteine or histidine residues by a zinc atom
  • multiple fingers typical
  • DNA response element
  • Enhancer


  • Type I Receptors
    • Sex hormone receptors (sex hormones) - Androgen receptor, Estrogen receptor, Progesterone receptor
    • Glucocorticoid receptor (glucocorticoids)
    • Mineralocorticoid receptor (mineralocorticoids)
  • Type II Receptors
    • Vitamin A receptor
    • Vitamin D receptor
    • Retinoid receptor
    • Thyroid hormone receptor
  • Orphan receptors


  • lipids acting as signaling molecules
  • act by binding to cell surface receptors
    • prostaglandins, prostacyclin, thromboxanes, and leukotrienes
  • rapidly broken down
  • act locally in autocrine or paracrine signaling pathways
  • synthesized from arachidonic acid
Links: Eicosanoid biosynthesis



Essential Cell Biology

  • Essential Cell Biology Chapter 15

Molecular Biology of the Cell

Alberts, Bruce; Johnson, Alexander; Lewis, Julian; Raff, Martin; Roberts, Keith; Walter, Peter New York and London: Garland Science; c2002

Molecular Cell Biology

Lodish, Harvey; Berk, Arnold; Zipursky, S. Lawrence; Matsudaira, Paul; Baltimore, David; Darnell, James E. New York: W. H. Freeman & Co.; c1999

The Cell- A Molecular Approach

Cooper, Geoffrey M. Sunderland (MA): Sinauer Associates, Inc.; c2000

Search Online Textbooks



  • PubMed is a service of the U.S. National Library of Medicine that includes over 18 million citations from MEDLINE and other life science journals for biomedical articles back to 1948. PubMed includes links to full text articles and other related resources. PubMed
  • PubMed Central (PMC) is a free digital archive of biomedical and life sciences journal literature at the U.S. National Institutes of Health (NIH) in the National Library of Medicine (NLM) allowing all users free access to the material in PubMed Central. PMC
  • Online Mendelian Inheritance in Man (OMIM) is a comprehensive compendium of human genes and genetic phenotypes. The full-text, referenced overviews in OMIM contain information on all known mendelian disorders and over 12,000 genes. OMIM
  • Entrez is the integrated, text-based search and retrieval system used at NCBI for the major databases, including PubMed, Nucleotide and Protein Sequences, Protein Structures, Complete Genomes, Taxonomy, and others Entrez

Search Pubmed


<pubmed>21346732</pubmed> <pubmed>18396093</pubmed>| PMC <pubmed>18163464</pubmed>] <pubmed>17189856</pubmed> <pubmed>17630848</pubmed>


External Links

2012 Course Content

Lectures: Cell Biology Introduction | Cells Eukaryotes and Prokaryotes | Cell Membranes and Compartments | Cell Nucleus | Cell Export - Exocytosis | Cell Import - Endocytosis | Cell Mitochondria | Cell Junctions | Cytoskeleton Introduction | Cytoskeleton - Intermediate Filaments | Cytoskeleton - Microfilaments | Cytoskeleton - Microtubules | Extracellular Matrix 1 | Extracellular Matrix 2 | Cell Cycle | Cell Division | Cell Death 1 | Cell Death 2 | Signal 1 | Signal 2 | Stem Cells 1 | Stem Cells 2 | 2012 Revision | Development

Laboratories: Introduction to Lab | Microscopy Methods | Preparation/Fixation | Immunochemistry | Cell Knockout Methods | Cytoskeleton Exercise | Confocal Microscopy | Microarray Visit | Tissue Culture 1 | Tissue Culture 2 | Stem Cells Lab | Stem Cells Analysis

2012 Projects: Group 1 | Group 2 | Group 3 | Group 4 | Group 5 | Group 6 | Group 7 | Group 8 | Group 9

Dr Mark Hill 2015, UNSW Cell Biology - UNSW CRICOS Provider Code No. 00098G