Anti-phospho-Ubiquitin (Ser57)

Ubiquitin (Ub) is initially produced as a 229 amino acids Polyubiquitin-B (UniProt: P0CG47) precursor protein encoded by the UBB gene (Gene ID: 7314) or a 685 amino acids Polyubiquitin-C precursor protein (UniProt: P0CG48) encoded by the UBC gene (Gene ID: 7316) in human. Ub exists either covalently attached to another protein, or free (unanchored). When covalently bound, it is conjugated to target proteins via an isopeptide bond either as a monomer (monoubiquitin), a polymer linked via different Lys residues of the ubiquitin (polyubiquitin chains) or a linear polymer linked via the initiator Met of the ubiquitin (linear polyubiquitin chains). Ub is linked covalently via its carboxyl terminus (Gly76) to usually Lys residues in target proteins. In a given target Lys residue can be linked to one single Ub molecule (monoubiquitylated) or to a chain of Ub molecules (polyubiquitylated). In a polyUb chain, Ub molecules can be linked through one of the seven Lys residues (K6, K11, K27, K29, K33, K48, and K63) or through the Ub N-terminus Met1 residue (which generates linear chains). Polyubiquitin chains, when attached to a target protein, have different functions depending on the Lys residue of the ubiquitin that is linked. For example, lysine 6-linked may be involved in DNA repair; lysine 11-linked is involved in endoplasmic reticulum-associated degradation (ERAD) and in cell-cycle regulation, and lysine 29-linked is involved in lysosomal degradation. Lysine 48-linked chains mark proteins for proteasomal degradation, while lysine 63-linked chains are involved in endocytosis, DNA-damage responses, and in signaling leading to activation of the transcription factor NF-kappa-B. Ubiquitin undergoes phosphorylation at the serine 57 by a ubiquitin kinase and this phosphorylation is an important modifier of ubiquitin function, particularly in response to proteotoxic stress. This phosphorylation may also be a deciding factor whether ubiquitin is recycled or degraded during multi-vesicular body sorting on endosomes. (Ref.: Hepowit, NL., et al (2020). eLife 9; e58155; Lee, S., et al. (2017) eLife. 6; e29176).

This rabbit polyclonal antibody specifically detects Ubiquitin phosphorylated on serine 57.

KLH-conjugated linear peptide corresponding to 10 amino acids surrounding phosphoserine 57 of human Ubiquitin.

Quality Control Testing

Evaluated by Western Blotting with a construct containing GST-tagged recombinant fragment of Ubiquitin phosphorylated on serine 57.

Western Blotting Analysis (WB): A 1:1,000 dilution of this antibody detected a construct containing GST-tagged recombinant Ubiquitin phosphorylated on serine 57, but did not react with non-phosphorylated construct. (Phospho-Ubiquitin construct: Courtesy of Dr. Jesse Rinehart, Yale University, School of Medicine).

Tested Applications

Affinity Binding Assay: A representative lot of this antibody bound phospho-Ubiquitin (ser57) peptide with a KD of 1.0 x 10-12 in an affinity binding assay.

Note: Actual optimal working dilutions must be determined by end user as specimens, and experimental conditions may vary with the end user

Anti-phospho-Ubiquitin (Ser57), Cat. No. ABS2206, is a rabbit polyclonal antibody that detects phospho-Ubiquitin (Ser57) and is tested for use in Affinity Binding Assay and Western Blotting.

Purified rabbit polyclonal antibody in buffer containing 0.1 M Tris-Glycine (pH 7.4), 150 mM NaCl with 0.05% sodium azide.

Recommend storage at +2°C to +8°C. For long term storage antibodies can be kept at -20°C. Avoid repeated freeze-thaws.

Concentration: Please refer to the Certificate of Analysis for the lot-specific concentration.

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