The MAPK cascade is a highly conserved signal transduction module that occurs throughout eukaryotic organisms. The control of the interactions between the various cascade components and their associated proteins is one level of control that exists to regulate the flow of information. The sterile alpha motif (SAM) was identified by searches for homologies between signal transduction proteins. Further database searches revealed that this 65-70 amino acid domain is found in approximately 70 proteins, whose function is involved in signal transduction or developmental regulation. SAM domains have been shown to mediate homo- and hetero-oligomerisation. For this report four SAM domains from the proteins STE50, STE11 (<I>Saccharomyces cerevisiae</I>), Ste4 and Byr2 (<I>Schizosaccharomyces pombe</I>) were cloned. All were expressed and purified successfully, and the solution structure of the STE50 SAM domain was determined. The homo- and heterotypic interactions of the STE50 SAM domain were also investigated using NMR, biophysical techniques such as analytical ultracentrifugation and dynamic light scattering, and by GST pull-down studies. Finally, residues important for the normal function of the STE50 SAM domain were identified by mutation.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:599743 |
| Date | January 2001 |
| Creators | Grimshaw, S. |
| Publisher | University of Cambridge |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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