p-Op18 Antibody (Ser 63): sc-12949

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Oncoprotein 18 (Op18) is a regulator of microtubule (MT) dynamics. Op18 is a target for both cell cycle and cell surface receptor-coupled kinase systems, and phosphorylation of Op18 on specific combinations of amino acid residues has been shown to switch off MT-destabilizing activity of Op18 (1,2). Induced expression of the catalytic subunit of cAMP-dependent protein kinase (PKA) results in a dramatic increase in cellular MT polymer content concomitant with phosphorylation and partial degradation of Op18 (2,3). Phosphorylation of Op18 on two specific sites, Serine 16 and Serine 63, is necessary and sufficient for PKA to switch off Op18 activity in intact cells (1,3,4). PKA phos-phorylation downregulates the MT-destabilizing activity of Op18, which in turn promotes increased tubulin polymerization (1,5). Op18 has the potential to regulate the MT system in response to external signals such as cAMP-linked agonists (1).