Effect of GbKTN1 fromGossypium barbadense on cell elongation of fission yeast (Schizosaccharomyces pombe)

Abstract

TheGbKTN1 gene was isolated from 10 DPA fiber cells ofGossypium barbadense using 5′RACE/3′RACE. Full-length cDNA of this gene is 2006 bp, including a 113 bp of 5′untranslated region, a 1563 bp of an open reading frame (ORF), and a 327 bp of 3′untranslated region (excluding the stop codon TAA). The ORF ofGbKTN1 encodes a 521-amino acid protein with a predicted size of 55 kD. Near C-terminal of the deduced protein there is a putative ATP binding site between amino acid residues from 233 to 414. Southern blot analysis indicated that theGbKTN1 was a single copy gene inG. barbadense. Combining semi-quantitative RT-PCR with Southern blot hybridization revealed thatGbKTN1 expressed in all the organs detected such as roots, stems, leaves and fibers. However, the mRNA ofGbKTN1 was the most abundant in fiber cells, while it was the lowest in leaves. TheGbKTN1 cDNA was transformed intoS. pombe to verify its function on cell elongation. Results showed that most yeast cells over expressingGbKTN1 gene were elongated dramatically with an average length increase of 2.18 times than that of the non-induced cells. Even the morphology of some yeast cells appeared irregularly. To the best of our knowledge this is the first evidence that KTN1 is correlated with cell elongationin vivo.