Erratum: Generation and analysis of innovative genomically humanized knockin SOD1, TARDBP (TDP-43), and FUS mouse models.

[This corrects the article DOI: 10.1016/j.isci.2021.103463.].

SGIP1 modulates kinetics and interactions of the cannabinoid receptor 1 and G protein-coupled receptor kinase 3 signalosome.

Cannabinoid receptor 1 (CB1R), a G protein-coupled receptor, plays a fundamental role in synaptic plasticity. Abnormal activity and deregulation of CB1R signaling result in a broad spectrum of pathological conditions. CB1R signaling is regulated by receptor desensitization including phosphorylation of residues within the intracellular C terminus by G protein-coupled receptor kinases (GRKs) that may lead to endocytosis. Furthermore, CB1R signaling is regulated by the protein Src homology 3-domain growth factor receptor-bound 2-like (SGIP1) that hinders receptor internalization, while enhancing CB1R association with ß-arrestin. It has been postulated that phosphorylation of two clusters of serine/threonine residues, 425 SMGDS429 and 460 TMSVSTDTS468 , within the CB1R C-tail controls dynamics of the association between receptor and its interaction partners involved in desensitization. Several molecular determinants of these events are still not well understood. We hypothesized that the dynamics of these interactions are modulated by SGIP1. Using a panel of CB1Rs mutated in the aforementioned serine and threonine residues, together with an array of Bioluminescence energy transfer-based (BRET) sensors, we discovered that GRK3 forms complexes with Gßγ subunits of G proteins that largely independent of GRK3's interaction with CB1R. Furthermore, CB1R interacts only with activated GRK3. Interestingly, phosphorylation of two specific residues on CB1R triggers GRK3 dissociation from the desensitized receptor. SGIP1 increases the association of GRK3 with Gßγ subunits of G proteins, and with CB1R. Altogether, our data suggest that the CB1R signalosome complex is dynamically controlled by sequential phosphorylation of the receptor C-tail and is also modified by SGIP1.

Generation and analysis of innovative genomically humanized knockin SOD1, TARDBP (TDP-43), and FUS mouse models.

Amyotrophic lateral sclerosis/frontotemporal dementia (ALS/FTD) is a fatal neurodegenerative disorder, and continued innovation is needed for improved understanding and for developing therapeutics. We have created next-generation genomically humanized knockin mouse models, by replacing the mouse genomic region of Sod1, Tardbp (TDP-43), and Fus, with their human orthologs, preserving human protein biochemistry and splicing with exons and introns intact. We establish a new standard of large knockin allele quality control, demonstrating the utility of indirect capture for enrichment of a genomic region of interest followed by Oxford Nanopore sequencing. Extensive analysis shows that homozygous humanized animals only express human protein at endogenous levels. Characterization of humanized FUS animals showed that they are phenotypically normal throughout their lifespan. These humanized strains are vital for preclinical assessment of interventions and serve as templates for the addition of coding or non-coding human ALS/FTD mutations to dissect disease pathomechanisms, in a physiological context.

Strain of Synechocystis PCC 6803 with Aberrant Assembly of Photosystem II Contains Tandem Duplication of a Large Chromosomal Region.

Cyanobacterium Synechocystis PCC 6803 represents a favored model organism for photosynthetic studies. Its easy transformability allowed construction of a vast number of Synechocystis mutants including many photosynthetically incompetent ones. However, it became clear that there is already a spectrum of Synechocystis "wild-type" substrains with apparently different phenotypes. Here, we analyzed organization of photosynthetic membrane complexes in a standard motile Pasteur collection strain termed PCC and two non-motile glucose-tolerant substrains (named here GT-P and GT-W) previously used as genetic backgrounds for construction of many photosynthetic site directed mutants. Although, both the GT-P and GT-W strains were derived from the same strain constructed and described by Williams in 1988, only GT-P was similar in pigmentation and in the compositions of Photosystem II (PSII) and Photosystem I (PSI) complexes to PCC. In contrast, GT-W contained much more carotenoids but significantly less chlorophyll (Chl), which was reflected by lower level of dimeric PSII and especially trimeric PSI. We found that GT-W was deficient in Chl biosynthesis and contained unusually high level of unassembled D1-D2 reaction center, CP47 and especially CP43. Another specific feature of GT-W was a several fold increase in the level of the Ycf39-Hlip complex previously postulated to participate in the recycling of Chl molecules. Genome re-sequencing revealed that the phenotype of GT-W is related to the tandem duplication of a large region of the chromosome that contains 100 genes including ones encoding D1, Psb28, and other PSII-related proteins as well as Mg-protoporphyrin methylester cyclase (Cycl). Interestingly, the duplication was completely eliminated after keeping GT-W cells on agar plates under photoautotrophic conditions for several months. The GT-W strain without a duplication showed no obvious defects in PSII assembly and resembled the GT-P substrain. Although, we do not exactly know how the duplication affected the GT-W phenotype, we hypothesize that changed stoichiometry of protein components of PSII and Chl biosynthetic machinery encoded by the duplicated region impaired proper assembly and functioning of these multi-subunit complexes. The study also emphasizes the crucial importance of a proper control strain for evaluating Synechocystis mutants.

A novel gain-of-function STAT1 mutation resulting in basal phosphorylation of STAT1 and increased distal IFN-γ-mediated responses in chronic mucocutaneous candidiasis.

Gain-of-function STAT1 mutations have recently been associated with autosomal dominant chronic mucocutaneous candidiasis (CMC). The purpose of this study was to characterize the three members of a non-consanguineous family, the father and his two sons, who presented with recurrent oral thrush and ocular candidiasis since early childhood. The three patients had reduced levels of IL-17-producing T cells. This reduction affected specifically IL-17(+)IFN-γ(-) T cells, because the levels of IL-17(+)IFN-γ(+) T cells were similar to controls. We found that PBMC (peripheral blood mononuclear cells) from the patients did not respond to Candida albicans ex vivo. Moreover, after polyclonal activation, patients' PBMC produced lower levels of IL-17 and IL-6 and higher levels of IL-4 than healthy controls. Genetic analyses showed that the three patients were heterozygous for a new mutation in STAT1 (c.894A>C, p.K298N) that affects a highly conserved residue of the coiled-coil domain of STAT1. STAT1 phosphorylation levels were significantly higher in patients' cells than in healthy controls, both in basal conditions and after IFN-γ stimulation, suggesting a permanent activation of STAT1. Cells from the patients also presented increased IFN-γ-mediated responses measured as MIG and IP-10 production. In conclusion, we report a novel gain-of-function mutation in the coiled-coil domain of STAT1, which increases STAT1 phosphorylation and impairs IL-17-mediated immunity. The mutation is responsible for CMC in this family with autosomal dominant inheritance of the disease.

The role of mannose-binding lectin in pneumococcal infection.

The role of mannose-binding lectin (MBL) deficiency (MBL2; XA/O and O/O genotypes) in host defences remains controversial. The surfactant proteins (SP)-A1, -A2 and -D, other collectins whose genes are located near MBL2, are part of the first-line lung defence against infection. We analysed the role of MBL on susceptibility to pneumococcal infection and the existence of linkage disequilibrium (LD) among the four genes. We studied 348 patients with pneumococcal community-acquired pneumonia (P-CAP) and 2,110 controls. A meta-analysis of MBL2 genotypes in susceptibility to P-CAP and to invasive pneumococcal disease (IPD) was also performed. The extent of LD of MBL2 with SFTPA1, SFTPA2 and SFTPD was analysed. MBL2 genotypes did not associate with either P-CAP or bacteraemic P-CAP in the case-control study. The MBL-deficient O/O genotype was significantly associated with higher risk of IPD in a meta-analysis, whereas the other MBL-deficient genotype (XA/O) showed a trend towards a protective role. We showed the existence of LD between MBL2 and SP genes. The data do not support a role of MBL deficiency on susceptibility to P-CAP or to IPD. LD among MBL2 and SP genes must be considered in studies on the role of MBL in infectious diseases.

Variants at the promoter of the interleukin-6 gene are associated with severity and outcome of pneumococcal community-acquired pneumonia.

PURPOSE: Conflicting results about the role of genetic variability at IL6, particularly the -174 G/C single nucleotide polymorphism (SNP), in sepsis have been reported. We studied the genetic variability at IL6 in patients with community-acquired pneumonia (CAP) and pneumococcal CAP (P-CAP). METHODS: This was a multicenter, prospective observational study. IL6 -174 was analyzed in 1,227 white Spanish patients with CAP (306 with P-CAP). IL6 1753 C/G (N = 750), 2954 G/C (N = 845), and haplotypes defined by these SNPs were also studied. RESULTS: In CAP patients the genotype -174 GG were associated with protection against acute respiratory distress syndrome (ARDS) (p = 0.008, OR = 0.4, 95% CI 0.2-0.8). No other significant associations were observed. However, in patients with P-CAP multivariate analysis adjusted for age, gender, co-morbidity, hospital of origin, and severity (pneumonia severity index, PSI) showed that the IL6 -174 GG genotype was protective against the development of ARDS (p = 0.002, OR = 0.25, 95% CI 0.07-0.79), septic shock (p = 0.006, OR = 0.46, 95% CI 0.18-0.79), and multiple organ dysfunction syndrome (p = 0.02, OR = 0.53, 95% CI 0.27-0.89). P-CAP patients homozygous for IL6 -174 G also showed a higher survival in a logistic regression analysis adjusted for age, gender, co-morbidity, hospital of origin, and PSI (p = 0.048, OR = 0.27, 95% CI 0.07-0.98). CONCLUSIONS: Our results indicate that the IL-6 -174 GG genotype is associated with lower severity and mortality in patients with P-CAP. This effect was higher than that observed in patients with CAP irrespective of the causal pathogen involved. Our results highlight the importance of the causal pathogen in genetic epidemiological studies in sepsis.

The Botrytis cinerea xylanase Xyn11A contributes to virulence with its necrotizing activity, not with its catalytic activity.

BACKGROUND: The Botrytis cinerea xylanase Xyn11A has been previously shown to be required for full virulence of this organism despite its poor contribution to the secreted xylanase activity and the low xylan content of B. cinerea hosts. Intriguingly, xylanases from other fungi have been shown to have the property, independent of the xylan degrading activity, to induce necrosis when applied to plant tissues, so we decided to test the hypothesis that secreted Xyn11A contributes to virulence by promoting the necrosis of the plant tissue surrounding the infection, therefore facilitating the growth of this necrotroph. RESULTS: We show here that Xyn11A has necrotizing activity on plants and that this capacity is conserved in site-directed mutants of the protein lacking the catalytic activity. Besides, Xyn11A contributes to the infection process with the necrotizing and not with the xylan hydrolyzing activity, as the catalytically-impaired Xyn11A variants were able to complement the lower virulence of the xyn11A mutant. The necrotizing activity was mapped to a 30-amino acids peptide in the protein surface, and this region was also shown to mediate binding to tobacco spheroplasts by itself. CONCLUSIONS: The main contribution of the xylanase Xyn11A to the infection process of B. cinerea is to induce necrosis of the infected plant tissue. A conserved 30-amino acids region on the enzyme surface, away from the xylanase active site, is responsible for this effect and mediates binding to plant cells.

Drill-assisted genomic DNA extraction from Botrytis cinerea.

Current DNA extraction protocols for genomic DNA from Botrytis cinerea almost always start with mycelium that has been reduced to powder with liquid N(2) in a mortar, and this makes their application to a large number of samples slow and cumbersome. Here we present an adaptation of an existing method [Möller et al. (1992) Nucleic Acids Res 20: 6115-6116] for which the initial steps have been modified, including the homogenization of the fungus with sand and the aid of a common household drill. This method allows the processing of large number of samples in much shorter times and generates an average of 4 mug DNA per sample, of sufficient quality for use in PCR and Southern blotting.

Methodological improvements in the expression of foreign genes and in gene replacement in the phytopathogenic fungus Botrytis cinerea.

SUMMARY Genetic transformation is generally carried out in Botrytis cinerea by random integration of the foreign DNA into the genome, resulting in transformants that show differences among them in, for example, the expression of a reporter gene. Here we report a system for site-directed integration in which a novel recipient strain containing a 5'-truncated copy of the hygromycin resistance gene, hph, is transformed with a vector containing another truncated copy, now in the opposite end, of the same selection marker. Homologous recombination in the region shared by these two truncated copies of hph is the only way by which antibiotic-resistant transformants can be generated. The transformation frequency obtained for the site-directed strategy was only three-fold lower than that of the standard transformation, and all the transformants had at least one copy of the plasmid integrated at the expected locus. This system was tested by the expression of the green fluorescent protein and we found that the levels of this protein were more homogeneous among the transformants, when compared with those obtained by random integration. On the other hand, in this paper, we also tried to optimize gene replacements in B. cinerea, which are generally carried out by transformation with an antibiotic resistance marker flanked by regions homologous to the target gene. We studied the influence of the length of these regions on the frequency of replacement of the B. cinerea gene cel5A. Lengths between 500 and 2000 bp gave similar frequencies (about 60%), while lengths of 100 bp decreased the frequency to 6%, showing that 500 bp is a convenient size that would give optimal gene replacement frequencies in this fungus.