RESUMO
MAIN CONCLUSION: A new Piper nigrum cysteine proteinase inhibitor, PnCPI, belonging to group I of phytocystatins, with inhibitory activity against papain and growth of Fusarium solani f. sp. piperis, was isolated and characterized. Previous studies (de Souza et al. 2011) have identified a partial cDNA sequence of putative cysteine proteinase inhibitor differentially expressed in roots of black pepper (P. nigrum L.) infected by F. solani f. sp. piperis. Here, we aimed to isolate the full-length cDNA and genomic sequences of the P. nigrum cysteine proteinase inhibitor gene, named PnCPI. Sequence analyses showed that the PnCPI gene encodes a deduced protein of 108 amino acid residues with a predicted molecular mass of 12.3 kDa and isoelectric point of 6.51. Besides the LARFAV-like sequence, common to all phytocystatins, PnCPI contains three conserved motifs of the superfamily cystatin: a glycine residue at the N-terminal region, the QxVxG reactive site more centrally positioned, and one tryptophan in the C-terminal region. PnCPI, belonging to group I of phytocystatins, showed high identity with cystatins isolated from several plant species. Sequence analyses also revealed no putative signal peptide at the N-terminal of PnCPI, as well as no introns within the genomic sequence corresponding to the PnCPI coding region. Molecular modeling showed the ability of PnCPI to interact with papain, while its inhibitory activity against this protease was confirmed after heterologous expression in Escherichia coli. The effects of heat treatments on the inhibitory activity of recombinant PnCPI, rPnCPI, were evaluated. In addition, rPnCPI exhibited in vitro activity against F. solani f. sp. piperis, revealing a new cystatin with the potential antifungal application. The identification of PnCPI as a functional cystatin able to inhibit the in vitro growth of F. solani f. sp. piperis indicates other factors contributing to in vivo susceptibility of black pepper to root rot disease.
Assuntos
Antifúngicos/farmacologia , Cistatinas/farmacologia , Inibidores de Cisteína Proteinase/farmacologia , Fusarium/efeitos dos fármacos , Papaína/antagonistas & inibidores , Piper nigrum/genética , Doenças das Plantas/prevenção & controle , Antifúngicos/isolamento & purificação , Clonagem Molecular , Inibidores de Cisteína Proteinase/isolamento & purificação , DNA Complementar/genética , Fusarium/enzimologia , Piper nigrum/química , Doenças das Plantas/microbiologiaRESUMO
AIM: To investigate the biocompatibility, type of cell death, osteogenic bioactivity and mRNA expression of the osteogenic markers, induced by CaneCPI-1 in human dental pulp cells (hDPCs). METHODOLOGY: hDPCs exposed to CaneCPI-1 and not exposed (control) were evaluated for cell viability by the 3-(4,5-dimethylthiazol)-2,5-diphenyltetrazolium bromide (MTT) assay; apoptosis by flow cytometry; alkaline phosphatase (ALP) activity by calculation of thymolphthalein release; gene expression of bone morphogenetic protein 2 (BMP-2), runt-related transcription factor 2 (RUNX2), ALP, osteocalcin (OC), bone sialoprotein (BSP) by qPCR; and mineralized nodules production by using alizarin red staining. The data were analysed by one-way analysis of variance (anova) and Turkey's post-test, two-way anova and Bonferroni post-test or t-test (P < 0.05). RESULTS: CaneCPI-1 induced no apoptosis and had no cytotoxic effect, except in the concentration of 33.20 µm, in which cell viability was significantly lower than the control (α-MEM nonosteogenic medium serum-free) (P < 0.05). There was significantly greater ALP activity, greater expression of the BMP-2, RUNX2, ALP, OC and BSP genes and greater mineralized nodules production in the CaneCPI-1 group in comparison with the control or osteogenic α-MEM control (α-MEM osteogenic medium - L-ascorbic acid and ß-glycerophosphate) (P < 0.05). CONCLUSIONS: CaneCPI-1 was cytocompatible and also induced the differentiation of hDPCs in osteogenic phenotype in vitro. CaneCPI-1 is a promising molecule to induce pulp repair.
Assuntos
Cisteína Proteases , Saccharum , Fosfatase Alcalina , Diferenciação Celular , Células Cultivadas , Inibidores de Cisteína Proteinase , Polpa Dentária , Humanos , Osteogênese , Cistatinas SalivaresRESUMO
Background Cysteine proteinase inhibitor (cystatin, CPI) is one of the most important molecules involved in plant development and defense, especially in the regulation of stress responses. However, it is still unclear whether the Jatropha curcas CPI (JcCPI) gene functions in salinity response and tolerance. In this study, the sequence of the JcCPI gene, its expression pattern, and the effects of overexpression in Escherichia coli and Nicotiana benthamiana were examined. The purpose of this study was to evaluate the regulatory role of JcCPI in salinity stress tolerance. Results The CPI gene, designated JcCPI, was cloned from J. curcas; its sequence shared conserved domains with other plant cystatins. Based on a transcription pattern analysis, JcCPI was expressed in all tissues examined, but its expression was highest in the petiole. Additionally, the expression of JcCPI was induced by salinity stress. A potential role of JcCPI was detected in transgenic E. coli, which exhibited strong CPI activity and high salinity tolerance. JcCPI was also transferred to tobacco plants. In comparison to wild-type plants, transgenic plants expressing JcCPI exhibited increased salinity resistance, better growth performance, lower malondialdehyde (MDA) contents, higher anti-oxidase activity, and higher cell viability under salinity stress. Conclusions Based on the results of this study, overexpression of JcCPI in E. coli and N. benthamiana conferred salinity stress tolerance by blocking cysteine proteinase activity. The JcCPI gene cloned in this study will be very useful for the development of stress-tolerant crops.