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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...
Autores principales: | , , |
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Formato: | Texto |
Lenguaje: | English |
Publicado: |
Oxford University Press
2010
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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 |
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. |
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