Phosphorylation disrupts the central helix in Op18/stathmin and suppresses binding to tubulin
AUTOR(ES)
Steinmetz, Michel O.
FONTE
Oxford University Press
RESUMO
Protein phosphorylation represents a ubiquitous control mechanism in living cells. The structural prerequisites and consequences of this important post-translational modification, however, are poorly understood. Oncoprotein 18/stathmin (Op18) is a globally disordered phosphoprotein that is involved in the regulation of the microtubule (MT) filament system. Here we document that phosphorylation of Ser63, which is located within a helix initiation site in Op18, disrupts the transiently formed amphipathic helix. The phosphoryl group reduces tubulin binding 10-fold and suppresses the MT polymerization inhibition activity of Op18’s C-terminal domain. Op18 represents an example where phosphorylation occurs within a regular secondary structural element. Together, our findings have implications for the prediction of phosphorylation sites and give insights into the molecular behavior of a globally disordered protein.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1083899Documentos Relacionados
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