Cloning and Characterization of a Ubiquitin Fusion Degradation Protein Gene in Wheat

摘要

Ubiquitin fusion degradation (UFD) protein, encoded by the UFD1 gene that was first described in yeast, is a key component in this Ub-dependent degradation system or Ub fusion degradation pathway. We isolated a UFD1 -like gene in wheat (Triticum aestivum L.) through RT-PCR. The entire coding region is 948 bp and encodes a polypeptide of 315 amino acids with 74% homology to a UFD1-like protein of Arabidopsis deposited in the GenBank. Its N-terminal possesses the so-called UFD1 domain highly conserved among eukaryotic organisms. This gene was designated as TUFD1 and mapped to group 6 chromosomes of wheat. Southern hybridization and database search demonstrated that UFD1 genes in plants are in single copy or low copies. Plant UFD1 proteins have three highly conserved C-terminal domains besides the UFD1 domain and are highly homologous to one another. TUFD1 showed a constitutive expression pattern in roots, stems, coleoptiles, and leaves of seedlings, and in young spikes and seeds at the hard-dough ripening stage.