EB3 (Ser-162), Phosphospecific Antibody

Microtubles (MTs) are oriented with a fast growing plus-end and a slower growing minus-end. The MT plus-end is a crucial site for the regulation of MT dynamics and MT association with different cellular organelles by several groups of plus-end tracking proteins (+TIPs) . These +TIPs form comet-like accumulations at the plus ends of MTs to regulate MT dynamics and interactions. The End-Binding (EB) family of +TIPs includes EB1 (MAPRE1), EB2 (MAPRE2, RP1), and EB3 (MAPRE3, EBF3) . EB proteins are ubiquitiously expressed +TIPs that can dimerize through a coiled-coil C-terminal region, and bind MTs through an N-terminal calponin homology domain. EB proteins can stabilize MTs, increase MT dynamics, and suppress MT pauses. Site specific phosphorylation may regulate EB activity. EB3 Ser-162 phosphorylation destabilizes EB3 dimer and reduces MT growth, while aurora-kinase induced Ser-176 phosphorylation regulates EB3 protein stability during mitosis.

The antibody detects a 32 kDa* protein corresponding to the apparent molecular mass of phosphorylated EB3 on SDS-PAGE immunoblots of mouse brain. This reactivity is significantly reduced after lambda phosphatase treatment. This peptide sequence is highly conserved in mouse and rat EB3, and is not conserved in EB1 and EB2.