cell communication
play

Cell Communication Topics 4.1 through 4.2 Topic 4.1 Cell Communication Importance of Cell Communication Cell signaling allows cells to communicate with one another and coordinate the functions/activities of the organism Communication

0 downloads 2 Views 1,8 MB Size Report
  1. Cell Communication Topics 4.1 through 4.2

  2. Topic 4.1 Cell Communication

  3. Importance of Cell Communication • Cell signaling allows cells to communicate with one another and coordinate the functions/activities of the organism • Communication pathways usually involve the plasma membrane

  4. Cell Communication • Cells communicate with one another through cell-to-cell contact or from a distance via chemical signaling • Correct and appropriate signal transduction pathways are generally under strong selective pressure

  5. Single-Celled Organisms (How Bacteria “Talk”, 18:14) • In single-celled organisms, cell communication pathways influence how the cell responds to its environment • Example: quorum sensing in bacteria

  6. Multicellular Organisms • In multicellular organisms, cell communication pathways coordinate the activities within individual cells that support the function of the organism as a whole • Example: Epinephrine stimulation of glycogen breakdown in mammals

  7. Cell Communication Cell-to-Cell Chemical Contact Signaling Local Plasmodesmata Regulators Immune Hormones System Cells

  8. Examples of Cell-to-Cell Contact

  9. Plasmodesmata • Microscopic channels which traverse the cell walls of plant cells and some algal cells, enabling transport and communication between them • Allow material to be transported from cell to cell (proteins, ions, etc.)

  10. Immune System Cells • Some immune cells interact by cell-to-cell contact • Examples include antigen-presenting cells (APCs), helper T-cells , and killer T-cells

  11. What are antigens and antibodies? • Antigen: any substance that causes the immune system to produce antibodies (“antibody - generating”) • Antibodies: Y-shaped proteins that are produced by B cells , identify and neutralize pathogens (antigens)

  12. How Antibodies Work

  13. Immune Cell: Antigen-Presenting Cell (Antigen Processing and Presentation Animation 2:30) • Antigen-presenting cells process and present antigens for recognition by certain lymphocytes such as T cells • Examples of antigen-presenting cells include macrophages , dendritic cells , and B cells

  14. MHC Molecules

  15. Immune Cell: Helper T • Helper T cells are the most important cells in adaptive immunity • Three ways in which helper T cells “help” the immune response: – stimulate B cells to produce more antibodies to the specific antigen – activate and increase the number of macrophages – activate cytotoxic (killer) T cells to kill infected cells

  16. Helper T Cells

  17. Immune Cell: Cytotoxic (Killer) T • Cytotoxic T cells target and destroy cells that are infected with pathogens

  18. Examples of Chemical Signaling

  19. Local Regulators • Local regulators are signaling molecules that only target cells in the vicinity of the signal emitting cell (short distance) • Examples of local regulators include neurotransmitters , morphogens , and quorum sensing

  20. Local Regulator: Neurotransmitters

  21. Local Regulator: Morphogens • Morphogens are a group of chemicals that are involved in the patterning of cells during embryonic development

  22. Local Regulator: Quorum Sensing • Bacteria produce and release chemical signal molecules called autoinducers that increase in concentration as a function of cell density

  23. Hormones • Hormones produced by endocrine cells travel long distances, through the blood, to reach their target cells • Examples of hormones include insulin and human growth hormone

  24. Insulin Signaling Pathway (Insulin Signaling Animation 4:42) • Insulin is produced by the pancreas and targets cells of the liver, skeletal muscle and fat

  25. Plant Hormones • Ethylene – gaseous hormone that ripens fruit • Auxin – chemical messenger that influences fruit development and cell growth

  26. Topic 4.2 Introduction to Signal Transduction

  27. Signal Transduction Pathway • The general pathway of signal transduction for cell-to-cell contact or chemical signaling is the same

  28. Signal Transduction Pathway Professor Dave Explains Signal Transduction (6:32)

  29. Signal Transduction • Signal transduction pathways link signal reception with a cellular response • Many signal transduction pathways include protein modification (shape change) and phosphorylation cascades

  30. Stage 1: Signal Reception • Signaling begins with the recognition of a chemical messenger – a ligand - by a receptor protein in a target cell • The ligand has a complementary shape to the receptor

  31. Ligand Types • The chemical messengers, or ligands, can be a peptide, a small chemical, or protein, in a specific one-to-one relationship with the receptor

  32. Types of Receptor Proteins • Receptor proteins may be embedded within the plasma membrane or located within the cytoplasm or nucleus

  33. Transmembrane Receptors • Embedded within the membrane, also known as extracellular receptors • Examples include GPCRs and ligand-gated ion channels

  34. G protein-coupled receptors (GPCRs) • An example of a receptor protein found in eukaryotes, thousands of different types • The epinephrine signaling pathway involves a GPCR

  35. Epinephrine Signaling Pathway Epinephrine Signaling Animation 3:10

  36. Ligand-Gated Ion Channels

  37. Intracellular Receptors • Located within the cytoplasm or nucleus • Targeted by lipid soluble ligands that are able to pass through the plasma membrane

  38. Stage 2: Signal Transduction • Signal transduction is the process by which a signal is converted to a cellular response • After the ligand binds, the intracellular domain of a receptor protein changes shape, initiating transduction of the signal • Occurs in one step or a series of many steps

  39. Signal Transduction • Signaling cascades relay signals from receptors to cell targets, often amplifying the incoming signals • Some signaling cascades utilize second messengers (such as cyclic AMP, or cAMP) during the signal transduction pathway to relay and amplify the intracellular signal

  40. Enzymes Involved in Signal Transduction • Protein kinases – turn “on” or activate proteins by adding phosphates to the proteins ( phosphorylation cascade ) • Protein phosphatases – turn “off” or deactivate proteins and kinases by removing phosphates from the proteins ( dephosphorylation )

  41. Second Messengers

  42. Stage 3: Cellular Response • The signal transduction pathway initiates a change in cellular activity • Response occurs in the cytoplasm or nucleus

  43. Cellular Response • Cellular responses include cell growth, secretion of molecules, or gene expression, among others • Most signaling pathways activate transcription factors that control the cellular response – Examples: Epidermal growth factor and testosterone

  44. Epidermal Growth Factor • Signaling pathway that promotes cell growth and division

  45. Testosterone Cellular response increases gene activity for proteins involved in: • Muscle mass • Bone growth • Body hair • Reproductive tissue

  46. Transcription Factors • Transcription factors regulate cellular responses by: - Turning “on” genes Protein OR - Turning “off” genes No protein OR - Regulating the activity of a particular protein

  47. Signal Transduction Review

Recommend Documents


cell communication 4 1 and 4 3 direct contact
Cell Communication 4.1 and 4.3 Direct

Cell Communication 4.1 and 4.3 Direct Contact What type of cell is this?

cell communication and cell signaling
Cell Communication and Cell Signaling

Cell Communication and Cell Signaling Why is cell signaling important? Why

cell communication
Cell Communication Communication

Cell Communication Cell Communication Communication between cells requires:

communication analysis of the communication analysis of
Communication Analysis of the

Communication Analysis of the Communication Analysis of the Communication

cell to cell signalling and communication during the
Cell to Cell signalling and

Cell to Cell signalling and communication during the establishment of the

investigating the effects of noise on a cell to cell
INVESTIGATING THE EFFECTS OF NOISE ON

INVESTIGATING THE EFFECTS OF NOISE ON A CELL-TO-CELL COMMUNICATION MECHANISM

bacterial relay race 09
Bacterial Relay Race 09 An

The TUDelft iGEM team presents: Bacterial Relay Race 09 An illustration of a

introducing simulated stem cells into a bio inspired cell
INTRODUCING SIMULATED STEM CELLS INTO

INTRODUCING SIMULATED STEM CELLS INTO A BIO-INSPIRED CELL- CELL COMMUNICATION

sk telecom
SK Telecom 1 U U U U U U U- U

U U U U U U U- U - - communication - - - - - communication

cells to tissues what we ll talk about
Cells to Tissues What well talk about

Cells to Tissues What well talk about Types and properties of tissues Cell

particle cell interactions and their
PARTICLE-CELL INTERACTIONS AND THEIR

PARTICLE-CELL INTERACTIONS AND THEIR IMPLICATIONS IN LUNG DEFENSE MECHANISMS

the major histocompatibility complex
The Major Histocompatibility Complex

The Major Histocompatibility Complex Peter Burrows 2008 4-6529

forget moonshots biomedicine needs an air traffic control
Forget Moonshots Biomedicine Needs an

Forget Moonshots Biomedicine Needs an Air Traffic Control System Jeff

5529 adxs11 001 immunotherapy 12 month survival and
5529 ADXS11-001 IMMUNOTHERAPY: 12

5529 ADXS11-001 IMMUNOTHERAPY: 12 MONTH SURVIVAL AND SAFETY DATA FROM A

with deep learning
with deep learning Mikhail Ignatov,

Designing cancer vaccines with deep learning Mikhail Ignatov, Applied

molecular determinants of factor viii immunogenicity
Molecular determinants of factor VIII

Molecular determinants of factor VIII immunogenicity Moderator Prof. dr.

immuno oncology applications
Immuno-Oncology Applications Lee S.

Immuno-Oncology Applications Lee S. Schwartzberg, MD, FACP West Clinic, P.C.;

hla alleles in the context of rams in therapy naive
HLA alleles in the context of RAMs in

University of Cologne Institute of Virology HLA alleles in the context of

innovative peptides
Innovative Peptides August 2019 Compa

plc Developing Innovative Peptides August 2019 Compa pany ny overv rview

sergio e baranzini ph d professor department of neurology
Sergio E. Baranzini, Ph.D.

Sergio E. Baranzini, Ph.D. Professor Department of Neurology, UCSF

briacell therapeutics corp
BriaCell Therapeutics Corp. OTCQB:

BriaCell Therapeutics Corp. OTCQB: BCTXF JULY 2016 TSX-V: BCT Forward-Looking

6
6 symptomatic rabies (2009)

Presentation by Dr Lindsay Nicholson LDA Conference 2011 Overview Immune