Mutations in the cyclin-dependent kinase-like 5 gene(CDKL5)cause a severe neurodevelopmental disorder,yet the impact of truncating mutations remains unclear.Here,we introduce the Cdkl5^(492stop) mouse model,mimicking ...Mutations in the cyclin-dependent kinase-like 5 gene(CDKL5)cause a severe neurodevelopmental disorder,yet the impact of truncating mutations remains unclear.Here,we introduce the Cdkl5^(492stop) mouse model,mimicking C-terminal truncating mutations in patients.492stop/Y mice exhibit altered dendritic spine morphology and spontaneous seizure-like behaviors,alongside other behavioral deficits.After creating cell lines with various Cdkl5 truncating mutations,we found that these mutations are regulated by the nonsense-mediated RNA decay pathway.Most truncating mutations result in CDKL5 protein loss,leading to multiple disease phenotypes,and offering new insights into the pathogenesis of CDKL5 disorder.展开更多
High incidence(10.2%)and mortality(9.2%)rates led to the ranking of colorectal cancer(CRC)as the second most malignant tumor spectrum worldwide in 2020.Treatment strategies are becoming highly dependent on the molecul...High incidence(10.2%)and mortality(9.2%)rates led to the ranking of colorectal cancer(CRC)as the second most malignant tumor spectrum worldwide in 2020.Treatment strategies are becoming highly dependent on the molecular characteristics of CRC.The classical theories accept two models depicting the origin of CRC:The progression of adenoma to cancer and transformation from serrated polyps to cancer.However,the molecular mechanism of CRC development is very complex.For instance,CRCs originating from laterally spreading tumors(LST)do not adhere to any of these models and exhibit extremely serious progression and poor outcomes.In this article,we present another possible pathway involved in CRC development,particularly from LST,with important molecular characteristics,which would facilitate the design of a novel strategy for targeted therapy.展开更多
The 1,2-rhamnosetransferase previously excavated from Citrus aurantium L.(CAVA)plants contains a prepeptide region.However,how this region regulates enzyme function and possible mechanism remain unknown.In this study,...The 1,2-rhamnosetransferase previously excavated from Citrus aurantium L.(CAVA)plants contains a prepeptide region.However,how this region regulates enzyme function and possible mechanism remain unknown.In this study,the conformational adjust mechanism of 1,2-rhamnosyltransferase derived from CAVA was explored through genetic modification.The enzymatic properties of N-terminal and C-terminal truncated mutants of the enzyme gene were studied.Results showed that compared to the wild-type,the truncated mutant 1,2RT△26-465 exhibited stronger affinity for the substrate.The catalytic efficiency(k_(cat)/K_(m))and specific enzyme activity increased by 20.3 times and 2.27 times,respectively.Circular dichroism(CD)analysis showed minimal changes in the secondary structure of the enzymes,yet there were significant differences in catalytic performance.Molecular docking analysis and kinetic simulations indicated that two enzymes could effectively promote the glycosylation of hesperetin-7-O-glucoside(HMG).Minor structural adjustments in the protein might alter the environment around the active site,resulting in the change in catalytic efficiency and stability.This study provides a straightforward and effective method for the industrial application of 1,2-rhamnosyltransferase.展开更多
基金supported by the Innovation of Science and Technology 2030-Major Project"Platform of Nonhuman Primate Models"(2021ZD0200900)the Ministry of Science and Technology(2018YFA0801404)+1 种基金the National Natural Science Foundation of China(82021001)the Shanghai Municipal Science and Technology Major Project.
文摘Mutations in the cyclin-dependent kinase-like 5 gene(CDKL5)cause a severe neurodevelopmental disorder,yet the impact of truncating mutations remains unclear.Here,we introduce the Cdkl5^(492stop) mouse model,mimicking C-terminal truncating mutations in patients.492stop/Y mice exhibit altered dendritic spine morphology and spontaneous seizure-like behaviors,alongside other behavioral deficits.After creating cell lines with various Cdkl5 truncating mutations,we found that these mutations are regulated by the nonsense-mediated RNA decay pathway.Most truncating mutations result in CDKL5 protein loss,leading to multiple disease phenotypes,and offering new insights into the pathogenesis of CDKL5 disorder.
基金Supported by the National Natural Science Foundation of China,No.72171170 and 82071964.
文摘High incidence(10.2%)and mortality(9.2%)rates led to the ranking of colorectal cancer(CRC)as the second most malignant tumor spectrum worldwide in 2020.Treatment strategies are becoming highly dependent on the molecular characteristics of CRC.The classical theories accept two models depicting the origin of CRC:The progression of adenoma to cancer and transformation from serrated polyps to cancer.However,the molecular mechanism of CRC development is very complex.For instance,CRCs originating from laterally spreading tumors(LST)do not adhere to any of these models and exhibit extremely serious progression and poor outcomes.In this article,we present another possible pathway involved in CRC development,particularly from LST,with important molecular characteristics,which would facilitate the design of a novel strategy for targeted therapy.
基金The Key R&D Program Projects in Guangdong,P.R.China(2023B0202040002)。
文摘The 1,2-rhamnosetransferase previously excavated from Citrus aurantium L.(CAVA)plants contains a prepeptide region.However,how this region regulates enzyme function and possible mechanism remain unknown.In this study,the conformational adjust mechanism of 1,2-rhamnosyltransferase derived from CAVA was explored through genetic modification.The enzymatic properties of N-terminal and C-terminal truncated mutants of the enzyme gene were studied.Results showed that compared to the wild-type,the truncated mutant 1,2RT△26-465 exhibited stronger affinity for the substrate.The catalytic efficiency(k_(cat)/K_(m))and specific enzyme activity increased by 20.3 times and 2.27 times,respectively.Circular dichroism(CD)analysis showed minimal changes in the secondary structure of the enzymes,yet there were significant differences in catalytic performance.Molecular docking analysis and kinetic simulations indicated that two enzymes could effectively promote the glycosylation of hesperetin-7-O-glucoside(HMG).Minor structural adjustments in the protein might alter the environment around the active site,resulting in the change in catalytic efficiency and stability.This study provides a straightforward and effective method for the industrial application of 1,2-rhamnosyltransferase.
