Biology subjects

Qi, P.

Publications and source records attributed to Qi, P..

3 recordsLinked to original sources

bioRxiv2018

Wheat avenin-like protein and its significant Fusarium Head Blight resistant functions

Wheat Avenin-like proteins (TaALP) are atypical storage proteins belonging to the Prolamin superfamily. Previous studies on ALPs have focused on the proteins positive effects on dough strength, whilst no correlation has been made between TaALPs and the plant immune system. Here, we performed genome-wide characterization of ALP encoding genes in bread wheat. In silico analyses indicated the presence of critical peptides in TaALPs that are active in the plant immune system. Pathogenesis-related nucleotide motifs were also identified in the putative promoter regions of TaALP encoding genes. RT-PCR was performed on TaALP and previously characterised pathogenesis resistance genes in developing wheat caryopses under control and Fusarium graminearum infection conditions. The results showed that TaALP and NMT genes were upregulated upon F. graminearum inoculation. mRNA insitu hybridization showed that TaALP genes were expressed in the embryo, aleurone and sub-aleurone layer cells. Seven TaALP genes were cloned for the expression of recombinant proteins in Escherichia coli, which displayed significant inhibitory function on F. graminearum under anti-fungal tests. In addition, FHB index association analyses showed that allelic variations of two ALP genes on chromosome 7A were significantly correlated with FHB symptoms. Over-expression of an ALP gene on chromosome 7A showed an enhanced resistance to FHB. Yeast two Hybridization results revealed that ALPs have potential proteases inhibiting effect on metacaspases and beta-glucosidases. A vital infection process related pathogen protein, F. graminearum Beta-glucosidase was found to interact with ALPs. Our study is the first to report a class of wheat storage protein or gluten protein with biochemical functions. Due to its abundance in the grain and the important multi-functions, the results obtained in the current study are expected to have a significant impact on wheat research and industry.

molecular biology↗

bioRxiv2018

Preliminary Study of the Potential Mechanism of CTSD in the Aging Process of Sepiella japonica: Fundamental Function Analysis

Cathepsin D, a kind of endopeptidase, can degrade peptides and proteins in lysosomes, which are involved in cell apoptosis. Previous transcriptome analysis of optic glands of Sepiella japonica across four growth stages, expression of a cathepsin D-like segment was found to be significantly different. Based on the complete cDNA sequence of S. japonica, the CTSD gene (also called sjCTSD, GenBank accession no. KY745896.1) was cloned using RACE amplification; this gene is 1389 bp in length and encodes proteins composed of 393 amino acids. Spatio-temporal expression profiles of the sjCTSD gene were determined using qPCR assays, which showed that the expression levels of sjCTSD constantly increased across four growth stages in 9 of 11 tissues that were investigated. In the optic glands, as well as pancreas and liver cells, sjCTSD expression levels sharply increased during the post-spawning phase. To investigate the potential role of the sjCTSD gene in aging progress, we constructed the prokaryotic expression vector of pET28a/sjCTSD. After induced by IPTG, the recombinant protein sjCTSD was obtained in the form of inclusion bodies, with a molecular size of approximately 40.3 kDa, the inclusion body of sjCTSD can be converted to soluble protein through the denaturation and renaturation. The results of functional experiments showed that sjCTSD could degrade bovine hemoglobin under acidic conditions, and inhibit the growth of Escherichia coli and Vibrio alginolyticus, which was speculated that the increased expression of sjCTSD may help inhibit the invasion of pathogenic bacteria with the immune function of cuttlefish declines during the aging process. To a certain extent, these results indicated the potential functional role of the sjCTSD gene in the aging process of S. japonica. This study provides insights to further understand the roles of lysosomal proteins on anti-aging effects in S. japonica and other cephalopoda species.

genetics↗

bioRxiv2018

RAD51 Enhances Zygotic Interhomolog Repair

Recent advances in genome editing have greatly improved knock-in (KI) efficiency1-9. Searching for factors to further improve KI efficiency for therapeutic use and generation of non-human primate (NHP) models, we found that the strand exchange protein RAD51 can significantly increase homozygous KI using CRISPR/Cas9 in mouse embryos through an interhomolog repair (IHR) mechanism. IHR is well-described in the context of meiosis10, but only occurs at low frequencies in mitotic cells11,12 and its existence in zygotes is controversial. Using a variety of approaches, we provide evidence for an endogenous IHR mechanism in zygotes that can be enhanced by RAD51. We show that this process can be harnessed for generating homozygous KI animals from wildtype zygotes based on exogenous donors and for converting heterozygous alleles into homozygous alleles without exogenous templates. Furthermore, we elucidate additional factors that contribute to zygotic IHR and identify a RAD51 mutant capable of insertion-deletion (indel)-free stimulation of IHR. Thus, our study provides conclusive evidence for the existence of zygotic IHR and demonstrates methods to enhance IHR for potential use in gene drives, gene therapy, and biotechnology.

molecular biology↗