title: Characterization and putative post-translational regulation of α- and β-tubulin gene families in Salix arbutifolia.
abstract: Microtubules, which are composed of heterodimers of α-tubulin (TUA) and β-tubulin (TUB) proteins, are closely associated with cellulose microfibril deposition and play pivotal roles in plant secondary cell wall development. In the present study, we identified eight TUA and twenty TUB genes in willow (Salix arbutifolia). Quantitative real-time PCR analysis showed that the small number of TUA gene family members relative to that of TUBs was complemented by a higher transcript copy number for each TUA gene, which is essential to the maintenance of the tubulin 1:1 heterodimer assembly. In Salix, five of eight TUAs were determined to be unusual because these contained a C-terminal methionine acid, leucine acid, glutamic acid, and glutamine acid, instead of the more typical tyrosine residue, which in turn generated the hypothesis of post-translational modifications (PTMs) that included deleucylation, demethiolation, deglutamynation, and deaspartylation. These PTMs are responsible for the removal of additional amino acid residues from TUAs prior to detyrosination, which is the first step of C-terminal PTMs. The additional PTMs of the TUA gene family might be responsible for the formation of different tubulin heterodimers that may have diverse functions for the adaptation of the woody perennial growth for Salix.
authors.affiliation: State Key Laboratory of Tree Genetics and Breeding, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, Republic of China.|Collaborative Innovation Center of Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, Republic of China.|Key Laboratory of Tree Breeding and Cultivation, State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, Republic of China.
authors.forename: Guodong
authors.initials: G
authors.lastname: Rao
authors.affiliation: State Key Laboratory of Tree Genetics and Breeding, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, Republic of China.|Key Laboratory of Tree Breeding and Cultivation, State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, Republic of China.
authors.forename: Yanfei
authors.initials: Y
authors.lastname: Zeng
authors.affiliation: State Key Laboratory of Tree Genetics and Breeding, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, Republic of China.|Key Laboratory of Tree Breeding and Cultivation, State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, Republic of China.
authors.forename: Caiyun
authors.initials: C
authors.lastname: He
authors.affiliation: State Key Laboratory of Tree Genetics and Breeding, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, Republic of China.|Collaborative Innovation Center of Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, Republic of China.|Key Laboratory of Tree Breeding and Cultivation, State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, Republic of China.
authors.forename: Jianguo
authors.initials: J
authors.lastname: Zhang
mesh_terms: D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D056726:Genetic Association Studies; D005810:Multigene Family; D010802:Phylogeny; D011499:Protein Processing, Post-Translational; D015203:Reproducibility of Results; D032108:Salix / Q000235:genetics* / Q000378:metabolism*; D014404:Tubulin / Q000235:genetics* / Q000378:metabolism*
chemical_list: D014404:Tubulin