N-myristoylation is a crucial covalent modification of numerous eukaryotic and viral proteins that is catalyzed by N-myristoyltransferase (NMT).
Ubiquitin is a small regulatory protein that plays an important role in the post-translational modification of numerous proteins, the addition of which often leads to protein aggregation or degradation [ 48].
Using IPP and mass spectrometry, the authors identified these proteins as small ubiquitin-like modifier activating enzyme 1 and 2 (SAE) that are involved in the post-translational modification of numerous targets, including protein kinases and transcription factors [ 49].
The occurrence of several post-translational modifications on numerous proteins has been well described, and it has been postulated that the interaction of such modifications governs complex regulatory processes, which are essential for proper protein function and for the regulation of diverse cellular events [ 3].
Among these, the prolyl-isomerase Pin1, a phospho-specific transducer of post-translational modifications for numerous key signaling molecules, surely is one of the most interesting.
Due to this post-translational modification, the role of numerous proteins is controlled by proteases, which then modulate a plethora of cellular mechanisms, such as cell growth, apoptosis, protein secretion, phagocytosis, signal transduction and extracellular matrix turnover (Puente et al, 2005).
Finally, surface modification has become a major field of work in biomaterial science to improve various aspects of currently available biomaterials, and we will describe the impact of numerous modifications of biomaterial surfaces on bacterial adhesion as well as a brief description of some biomaterial modifications designed to create so-called bacteria-repellent biomaterials.
It is now recognized that epigenetic modifications control the expression of numerous genes via the regulation of promoter accessibility to transcriptional factors.
The possibility of numerous modifications occurring on a single residue, like the preponderance of lysine PTMs discussed above, raises questions about how these modifications are modulated either temporally or physically to create a functional readout.
The stress response consists of numerous modifications to an organism's physiology and behaviour that are necessary to regain and maintain homeostasis once it has been challenged by changes in the environment, e.g. changes in temperature [ 2].
