PTMScan^® Sumoylation Remnant Motif Kit #92465

Small ubiquitin-related modifier 1, 2, and 3 (SUMO-1, -2, and -3) are members of the ubiquitin-like protein family (1). The covalent attachment of the SUMO-1, -2, or -3 (SUMOylation) to target proteins is analogous to ubiquitination. This post-translational modification is a reversible, multi-step process that is initiated by cleaving a precursor protein to a mature protein. Mature SUMO-1, -2, or -3 is then linked to the activating enzyme E1 and conjugated to E2. In conjunction with E3, SUMO-1, -2, or -3 is ligated to the target protein (2). Ubiquitin and the individual SUMO family members are all targeted to different proteins with diverse biological functions. Ubiquitin predominantly regulates degradation of its target (1). In contrast, SUMO-1 is conjugated to RanGAP, PML, p53, and IκB-α to regulate nuclear trafficking, formation of subnuclear structures, regulation of transcriptional activity, and protein stability (3-7). SUMO-2/-3 forms poly-(SUMO) chains, is conjugated to topoisomerase II and APP, regulates chromosomal segregation and cellular responses to environmental stress, and plays a role in the progression of Alzheimer disease (8-11).

In this assay, PTMScan^® Branch Motif (K-ε-GG) Immunoaffinity Beads, a proprietary branch (“K-ε-GG”) antibody with specificity for a di-glycine tag that is the remnant of SUMO left on protein substrates after WaLP digestion, is used to enrich sumoylated peptides from WaLP-digested cell samples. This enrichment is followed by LC-MS/MS analysis for quantitative profiles of hundreds to over a thousand non-redundant sumoylated sequences.