Risk homozygous haplotype regions for autism identifies population-specific ten genes for numerous pathways

Background Recessive homozygous haplotype (rHH) mapping is a reliable tool for identifying recessive genes by detecting homozygous segments of identical haplotype structures. These are shared at a higher frequency amongst probands compared to parental controls. Finding out such rHH blocks in autism subjects can help in deciphering the disorder etiology. Objectives The study aims to detect rHH segments of identical haplotype structure shared at a higher frequency in autism subjects than controls to identify recessive genes responsible for autism manifestation. Methods In the present study, 426 unrelated autism genotyped probands with 232 parents (116 trios) were obtained from Gene Expression Omnibus (GEO) Database. Homozygosity mapping analyses have been performed on the samples using standardized algorithms using the Affymetrix GeneChip® 500K SNP Nsp and Sty mapping arrays datasets. Results A total of 38 homozygous haplotype blocks were revealed across sample datasets. Upon downstream analysis, 10 autism genes were identified based on selected autism candidate genes criteria. Further, expressive Quantitative Trait Loci (QTL) analysis of SNPs revealed various binding sites for regulatory proteins BX3, FOS, BACH1, MYC, JUND, MAFK, POU2F2, RBBP5, RUNX3, and SMARCA4 impairing essential autism genes CEP290, KITLG, CHD8, and INS2. Pathways and processes such as adherens junction, dipeptidase activity, and platelet-derived growth factor—vital to autism manifestation were identified with varied protein-protein clustered interactions. Conclusion These findings bring various population clusters with significant rHH genes. It is suggestive of the existence of common but population-specific risk alleles in related autism subjects.

Fruit ripening-associated leucylaminopeptidase with cysteinylglycine dipeptidase activity from durian suggests its involvement in glutathione recycling

Background Durian (Durio zibethinus L.) is a highly popular fruit in Thailand and several other Southeast Asian countries. It is abundant in essential nutrients and sulphur-containing compounds such as glutathione (GSH) and γ-glutamylcysteine (γ-EC). Cysteinylglycine (Cys-Gly) is produced by GSH catabolism and occurs in durian fruit pulp. Cysteine (Cys) is a precursor of sulphur-containing volatiles generated during fruit ripening. The aforementioned substances contribute to the strong odour and flavour of the ripe fruit. However, the genes encoding plant Cys-Gly dipeptidases are unknown. The aim of this study was to measure leucylaminopeptidase (LAP) activity in durian fruit pulp. Results We identified DzLAP1 and DzLAP2, which the former was highly expressed in the fruit pulp. DzLAP1 was expressed at various ripening stages and in response to ethephon/1-MCP treatment. Hence, DzLAP1 is active at the early stages of fruit ripening. DzLAP1 is a metalloenzyme ~ 63 kDa in size. It is activated by Mg2+ or Mn2+ and, like other LAPs, its optimal alkaline pH is 9.5. Kinetic studies revealed that DzLAP1 has Km = 1.62 mM for its preferred substrate Cys-Gly. DzLAP1-GFP was localised to the cytosol and targeted the plastids. In planta Cys-Gly hydrolysis was confirmed for Nicotiana benthamiana leaves co-infiltrated with Cys-Gly and expressing DzLAP1. Conclusions DzLAP1 has Cys-Gly dipeptidase activity in the γ-glutamyl cycle. The present study revealed that the LAPs account for the high sulphur-containing compound levels identified in fully ripened durian fruit pulp.

Inhibition of Human Cathepsins B and L by Caffeic Acid and Its Derivatives

Caffeic acid (CA) and its derivatives caffeic acid phenethyl ester (CAPE) and chlorogenic acid (CGA) are phenolic compounds of plant origin with a wide range of biological activities. Here, we identify and characterize their inhibitory properties against human cathepsins B and L, potent, ubiquitously expressed cysteine peptidases involved in protein turnover and homeostasis, as well as pathological conditions, such as cancer. We show that CAPE and CGA inhibit both peptidases, while CA shows a preference for cathepsin B, resulting in the strongest inhibition among these combinations. All compounds are linear (complete) inhibitors acting via mixed or catalytic mechanisms. Cathepsin B is more strongly inhibited at pH 7.4 than at 5.5, and CA inhibits its endopeptidase activity preferentially over its peptidyl-dipeptidase activity. Altogether, the results identify the CA scaffold as a promising candidate for the development of cathepsin B inhibitors, specifically targeting its endopeptidase activity associated with pathological proteolysis of extracellular substrates.

Fruit ripening-associated leucylaminopeptidase with cysteinylglycine dipeptidase activity from durian suggests its involvement in glutathione recycling

Background: Durian ( Durio zibethinus L.) is a highly popular fruit in Thailand and several other Southeast Asian countries. It is abundant in essential nutrients and sulphur-containing compounds such as glutathione (GSH) and γ-glutamylcysteine (γ-EC). Cysteinylglycine (Cys-Gly) is produced by GSH catabolism and occurs in durian fruit pulp. Cysteine (Cys) is a precursor of sulphur-containing volatiles generated during fruit ripening. The aforementioned substances contribute to the strong odour and flavour of the ripe fruit. However, the genes encoding plant Cys-Gly dipeptidases are unknown. The aim of this study was to measure leucylaminopeptidase (LAP) activity in durian fruit pulp. Results: We identified DzLAP1 and DzLAP2, which the former was highly expressed in the fruit pulp. DzLAP1 was expressed at various ripening stages and in response to ethephon/1-MCP treatment. Hence, DzLAP1 is active at the early stages of fruit ripening. DzLAP1 is a metalloenzyme ~ 63 kDa in size. It is activated by Mg 2+ or Mn 2+ and, like other LAPs, its optimal alkaline pH is 9.5. Kinetic studies revealed that DzLAP1 has K m = 1.62 mM for its preferred substrate Cys-Gly. DzLAP1-GFP was localised to the cytosol and targeted the plastids. In planta Cys-Gly hydrolysis was confirmed for Nicotiana benthamiana leaves co-infiltrated with Cys-Gly and expressing DzLAP1 . Conclusions: DzLAP1 has Cys-Gly dipeptidase activity in the γ-glutamyl cycle. The present study revealed that the LAPs account for the high sulphur-containing compound levels identified in fully ripened durian fruit pulp.

Fruit ripening-associated leucylaminopeptidase with cysteinylglycine dipeptidase activity from durian suggests its involvement in glutathione recycling

BackgroundDurian (Durio zibethinus M.) is a highly popular fruit in Thailand and several other Southeast Asian countries. It is abundant in essential nutrients and several sulphur-containing compounds such as glutathione (GSH) and γ-glutamylcysteine (γ-EC). Cysteinylglycine (Cys-Gly) generated by GSH catabolism is also found in durian fruit pulp. Cysteine (Cys) is a precursor of the sulphur-containing volatiles produced during durian fruit ripening and accounting for the strong odour and flavour of the ripe fruit. However, the genes encoding plant Cys-Gly dipeptidases have seldom been identified. Our aim was to analyse the Cys-Gly peptidase activity of leucylaminopeptidase (LAP) in durian fruit pulp. ResultsDzLAP1 and DzLAP2 were identified, which the former was highly expressed in the fruit pulp. DzLAP1 expression at various ripening stages and in response to ethephon/1-MCP treatments suggested that DzLAP1 is active and important at the early stages of fruit ripening. Biochemical characterisation showed that DzLAP1 is a metalloenzyme activated by Mg2+ or Mn2+, is approximately 63 kDa in size, and has an optimal alkaline pH of 9.5 which is typical of LAPs. Kinetic studies revealed that DzLAP1 had a Km of 1.62 mM for its preferred substrate Cys-Gly. DzLAP1-GFP was localised to the cytosol and targeted to the plastids. ConclusionsDzLAP1 has Cys-Gly dipeptidase activity in the γ-glutamyl cycle. The present study discloses that the LAPs identified in durian fruit pulp are implicated in the high sulphur-containing compound levels observed at full ripening.

Staphylococcus aureus VRSA-11B Is a Constitutive Vancomycin-Resistant Mutant of Vancomycin-Dependent VRSA-11A

ABSTRACTVancomycin-resistantStaphylococcus aureusVRSA-10 was isolated in 2009, whereas VRSA-11A and VRSA-11B were isolated from the same patient in 2010. Growth curves and determination of the nature of the peptidoglycan precursors and of the VanXd,d-dipeptidase activity in the absence and in the presence of vancomycin indicated that vancomycin resistance was inducible in VRSA-10, that VRSA-11A was partially dependent on glycopeptide for growth, and that VRSA-11B was constitutively resistant. Both VRSA-11A and -11B harbored an insertion sequence, ISEf1, at the same locus in thevanX-vanYintergenic region of Tn1546and an S183A mutation in the chromosomald-alanyl:d-alanine ligase (Ddl). This substitution has been shown to be responsible for a drastic diminution of the affinity of the enzyme ford-Ala at subsite 1 inEscherichia coliDdlB. VRSA-11B exhibited an additional mutation, P216T, in the transcriptional regulator VanR, most probably associated with constitutive expression of vancomycin resistance. It is thus likely that VRSA-11B is a constitutive derivative of VRSA-11A selected during prolonged vancomycin therapy. Synthesis of peptidoglycan precursors ending ind-Ala-d-lactate was responsible for oxacillin susceptibility of VRSA-11A and VRSA-11B despite the presence of a wild-typemecAgene in both strains.