|Module Title||CELL SIGNALLING AND RECOGNITION|
|Co-ordinator||Dr Richard Kemp|
|Other staff||Dr Paul Kenton, Dr Luis Mur|
|Pre-Requisite||BS23020 , BS22320|
|Course delivery||Lecture||30 Hours|
|Assessment||Exam||3 Hours One 3-hour theory paper||20%|
|Resit assessment||2 Hours One 3-hour theory exam (plus resubmission of failed parts of continuous assessment or an alternative)|
Aims and objectives
One of the most important properties of cells in multicellular organisms is intercellular communication by small hydrophilic molecules. This is the major way to integrate the life and growth of higher organisms. Organisms are so complex that there must be a myriad of signals, receptors and cascades. There is, however, a relatively small number of major systems. The aim of this module is to explain the principal features of these pathways by reference to six topics of significant common interest to biologists. The objective is to highlight the common theme of signal reception, membrane transduction, initiation of cascades and downstream regulation of cellular processes.
The aim and objective will be met by considering the following representative topics:
Mitogenesis. Mitogenic signalling via receptor tyrosine kinases (RTKs) will be examined, discussing RTK activation, what role this plays in recruitment, via adaptor proteins, of downstream signalling mediators (p21ras and phospholipase C), how these components trigger kinase cascades and ultimately how transcription factor activity is modulated.
Hormones and metabolism. Structure of receptors for insulin, insulin-like growth factor and noradrenaline with the respective cytoplasmic RTK and G-protein cascades. For insulin, role of receptor-mediated endocytosis with recycling pathway between membrane and endosome with internalisation signals and modulation. Protein kinase cascades (and modulating phosphatases) to change glycogen and glycolytic metabolism with resulting effects on cells.
Key signalling cascades in the inflammatory response. The signalling cascade associated with major inflammatory cytokine, interleukin-1 (IL-1) leading to activation of NF-kB transcription factor and phospholipase A2 leading the synthesis of prostaglandins will be described. These pathways will be used to illustrate the suppressive effects of glucocorticoid steroids and analgesic drugs.
Movement and Adhesion. Critical role of integrin transduction at the membrane for signalling to involve small GTPase Rho and MAP kinase with downstream effect on cytoskeleton and initiate whole cell and localised movement. Rho also regulates cell-extracellular matrix and cell-cell adhesion. Control movement and adhesion by association of integrins with transmembrane syndecans and cadherins with the cytoskeleton.
Calcium. Signalling via calcium depends on the maintaining a steep concentration gradient between calcium stores and the cytosol. We shall examine how this gradient is established, how calcium flux is regulated, and how changes in calcium concentration are `detected' by proteins such as calmodulin. Techniques in calcium research will also be discussed.
Light quality as a developmental cue in plants. The phytochrome family of photoreceptors monitor the quality and quantity of light to regulate e.g. chloroplast development, growth patterns and flowering. This is dependent on phytochrome 'switching' between inactive (Pr) and active (Pfr) forms in response to far-red, and red light wavelengths respectively. The diverse actions of Pfr will be considered in detail as an introduction to signalling in plants.
On completion of this module the student should
** Multiple Copies In Hugh Owen
Alberts, B., BRay, D., Lewis, J., ROberts, K. & Watson, D.. (1994) Molecular biology of the cell. 3rd. New York, Garland Publisher.
Heldin, C-H. & Purton, M.. (1996) Signal transduction. Modular texts in molecular and cell biology. London, Chapman & Hall.