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Plant cell division is specifically affected by nitrotyrosine

Virtually all eukaryotic α-tubulins harbour a C-terminal tyrosine that can be reversibly removed and religated, catalysed by a specific tubulin–tyrosine carboxypeptidase (TTC) and a specific tubulin–tyrosine ligase (TTL), respectively. The biological function of this post-translational modification...

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Detalles Bibliográficos
Autores principales: Jovanović, Aleksandra M., Durst, Steffen, Nick, Peter
Formato: Texto
Lenguaje:English
Publicado: Oxford University Press 2010
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2814120/
https://www.ncbi.nlm.nih.gov/pubmed/20018903
http://dx.doi.org/10.1093/jxb/erp369
Descripción
Sumario:Virtually all eukaryotic α-tubulins harbour a C-terminal tyrosine that can be reversibly removed and religated, catalysed by a specific tubulin–tyrosine carboxypeptidase (TTC) and a specific tubulin–tyrosine ligase (TTL), respectively. The biological function of this post-translational modification has remained enigmatic. 3-nitro-L-tyrosine (nitrotyrosine, NO(2)Tyr), can be incorporated into detyrosinated α-tubulin instead of tyrosine, producing irreversibly nitrotyrosinated α-tubulin. To gain insight into the possible function of detyrosination, the effect of NO(2)Tyr has been assessed in two plant model organisms (rice and tobacco). NO(2)Tyr causes a specific, sensitive, and dose-dependent inhibition of cell division that becomes detectable from 1 h after treatment and which is not observed with non-nitrosylated tyrosine. These effects are most pronounced in cycling tobacco BY-2 cells, where the inhibition of cell division is accompanied by a stimulation of cell length, and a misorientation of cross walls. NO(2)Tyr reduces the abundance of the detyrosinated form of α-tubulin whereas the tyrosinated α-tubulin is not affected. These findings are discussed with respect to a model where NO(2)Tyr is accepted as substrate by TTL and subsequently blocks TTC activity. The irreversibly tyrosinated α-tubulin impairs microtubular functions that are relevant to cell division in general, and cell wall deposition in particular.