Order Description

exam (try the structure of essay to be easy to memorise)
not more than 800 words
some the references should be updated within 3-4 years and tray to avoid review articles

Discuss, giving specific examples, the use of antibodies for the study of cell signalling involving

protein kinase cascades. Your answer should include any advantages and/or disadvantages and

reference to practical considerations when using such antibodies.

General introduction to the role of protein kinases in signal transduction including the two main

families (serine/threonine kinases and tyrosine kinases). Reference to the general uses of

antibodies to study cell signaling pathways e.g. the use of antibodies to immunoprecipitate cell

signalling proteins and the localisation of proteins via immunohistochemistry, immunocytochemistry

may also be included.

The main focus of the answer should highlight the importance of protein phosphorylation in cell

signaling lead to the development of anti phospho-tyrosine antibodies (attempts to produce anti

phospho-serine and anti phospho-threonine – less successful). Also the development of phospho-

specific antibodies has revolutionized the study of signaling pathways using antibodies.

Advantages: no need to use isotopes, can target specific phosphorylation sites. Disadvantages: may

miss activation of a specific protein kinase if additional (and perhaps unknown) pathways of

activation exist that are independent of the phospho-specific antibody used. Practical

considerations i.e. must inhibit phosphatase activity, choice of immunoprecipitating antibody,

protein levels etc. Specific examples include the MAPK pathway and BAD phosphorylation.

Additional marks awarded for evidence of background reading.