Although there are over 200 types of PTMs described in the literature, there are only a handful that have been studied in great detail, of these serine/threonine phosphorylation, tyrosine phosphorylation (pY), acetylation (Ac), ubiquitination (Ub) and SUMOylation (SUMO) have been shown to be key regulators in almost all cellular processes, including signal transduction, epigenetics, gene and protein expression, protein stability and localization, and cellular immunity.  Learn more about these key regulatory protein modifications and the Signal-Seeker™ tools used to study them by clicking on the options below.