Rabbit Polyclonal Antibody

Antigen/Purification: ExpandCollapse

Phosphopeptide corresponding to amino acid residues surrounding the phospho-Ser³²⁶ of human CtIP.

The antibody is prepared from pooled rabbit serum by affinity purification via sequential chromatography on phospho- and dephosphopeptide affinity columns.

Biological Significance: ExpandCollapse

CtIP, C-terminal binding protein-interacting protein, is a DNA endonuclease activated by double stranded breaks (DSBs).  DSB repairs can be performed by either one of two mechanisms; non-homologous end joining (NHEJ) or homologous recombination (HR).  NHEJ is the predominant DSB repair pathway throughout the entire cell cycle, most importantly in the G1 phase (Rothkamm et al, 2003); while HR is important for repairing DSBs in S and G2 phases (Beucher et al, 2009). CtIP controls DSB resection; an event that only occurs in HR during G2-phase. Phosphorylation of Thr⁸⁴⁷ dictates the resection efficiency (Huertas et al, 2008). Furthermore, it has been found that DSBs undergo resection and repair in G1-phase cells via a process requiring Plk3 phosphorylation of CtIP at Ser³²⁷ and Thr⁸⁴⁷ (Barton et al, 2014).  Several additional phosphorylation sites within CtIP have been identified, but their significance in the repair of DNA have yet to be determined.

Storage

100 µl in 10 mM HEPES (pH 7.5), 150 mM NaCl, 100 µg BSA per ml and 50% glycerol. Adequate amount of material to conduct 10-mini Western Blots.

For long term storage –20° C is recommended. Stable at –20° C for at least 1 year.

General References

Rothkamm K, Kruger I, Thompson LH, Lobrich M (2003) Pathways of DNA double-strand break repair during the mammalian cell cycle. Mol Cell Biol., 23, 5706-5715.

Beucher A, Birraux J, tchouandong L, Baron O, Shibata A, Conrad S, Goodarzi AA, Krempler A, Jeggo PA, Lobrich M (2009) ATM and Artemis promote homologous recombination of radiation-inducted DNA double-strand breaks in G2. EMBO J., 28, 3413-3427.

Huertas P, Jackson SP (2008) Human CtIP Mediates Cell Cycle Control of DNA End Resection and Double Strand Break Repair . J. Biol. Chem, 284: 9558-9565.

Olivia Barton, Steffen C Naumann, Ronja Diemer-Biehs, Julia Künzel, Monika Steinlage, Sandro Conrad, Nodar Makharashili, Jiadong Wang, Lin Fent,Bernard S. Lopez, Tanya T. Paull, Junjie Chen, Penny A Jeggo, and Markus Löbrich (2014) Polo-like Kinase 3 regulates CtIP during DNA double-strand break repair in G1. JCB,  Nov 7;206(7): 877-894.