ABSTRACT
In this study, RACE technology was employed to isolate the full length cDNA of DoHT1 in Dendrobium officinale, followed by bioinformatics analysis of the sequence characteristics. And the expression pattern of the gene was also analyzed by quantitative PCR. The full length cDNA of DoHT1 was 1 586 bp in length, containing a 1 536 bp ORF, which encoded a 511-aa protein with molecular weight of 56.18 kD and isoelectric point of 9.08. The deduced DoHT1 protein had the major facilitator superfamily conserved domain (22-483), SUGAR₋TRANSPORT₋1 (139-164), and SUGAR₋TRANSPORT₋2 (338-355), typical for sugar transporter; DoHT1, without a single peptide had 11 transmembrane regions, and was predicted to locate in the plasma membrane; DoHT1 had high identities (54.7%-80.7%) with HTs proteins from various plants. DoHT1 belonged to the MST (monosaccharide transporter) group of the evolutionary tree, and was closely related to the Phalaenopsis equestris. DoHT1 was differentially expressed in the three included organs. The transcripts were significantly the most abundant in the leaves with 19.36 fold than roots, then 1.82 fold in the stems than the roots. The identification and molecular characterization of the full length DoHT1 will be essential for further function study of the gene during the regulation of sugar metabolism of D. officinale.
ABSTRACT
Glucose was transported by the large number of hexose transporters in yeast cells. There were 18 hexose transporter genes had been identified in Saccharomyces cerevisiae. However,as an excellent expression system,there was no information of these genes had been reported in Pichia pastoris. Based on high homologous recombination efficiency in yeast,we chose G418 resistance for screening,200 bp were cloned from the up and down sequences of HXT1 ORF respectively,then ligated to the 5′ and 3′ end of G418 resis-tance gene for recombination. After electroporation of GS115 spheroplast and screened through different G418 concentration plates,finally we obtained one HXT1 gene deletion mutant named GS115?HXT1. The growth rate and glucose consumption of this mutant were both lower than the wide type.
ABSTRACT
Objective] To amplify,clone and express of a gene encoding hexose transporter of Plasmodium falcipuram(PfHT1) from Southern China isolate FCC1/HN for studing the immune of recombinant which protective from malaria parasite infection. [Methods] Cultivation of P.falciparum isolate FCC1/HN in vitro; extraction of genomic DNA from FCC1/HN using the alkali specific cleavage method; PCR amplification of PfHT1 and cloning into eukaryotic expression vector, pEGFPN3. The recombinant was introduced into mammalian cells, HEPG2 by using liposome\|mediated transfection. [Results] The gene encoding PfHT1 was specifically amplified from the genomic DNA of P.falciparum isolate FCC1/HN. The size of amplified fragment was 1 516 base pair. The eukaryotic expression recombinant, pN3\|HT1 , was constructed and expressed steadily in the hepatocarcinoma cell lines, HEPG2. [Conclusion] The gene encoding PfHT1 was successfully amplified and cloned. The pN3\|HT1/HEPG2 cell line was built for expressing fusion protein of GFP\|HT1.