Metabolic interaction between anthocyanin and lignin biosynthesis is associated with peroxidase FaPRX27 in strawberry fruit Ring , Ludwig (Technische Universitat Munchen, Freising(Allemagne). Biotechnology of Natural Products); Yeh , Su-Ying (Technische Universität München, Freising(Allemagne). Biotechnology of Natural Products); Hücherig , Stephanie (Technische Universität München, Freising(Allemagne). Biotechnology of Natural Products) ...
http://www.plantphysiol.org,
2013, Letnik:
1
Publication
Plant phenolics have drawn increasing attention due to their potential nutritional benefits. Although the basic reactions of the phenolics biosynthetic pathways in plants have been intensively ...analyzed, the regulation of their accumulation and flux through the pathway is not that well established. The aim of this study was to use a strawberry (Fragaria × ananassa) microarray to investigate gene expression patterns associated with the accumulation of phenylpropanoids, flavonoids, and anthocyanins in strawberry fruit. An examination of the transcriptome, coupled with metabolite profiling data from different commercial varieties, was undertaken to identify genes whose expression correlated with altered phenolics composition. Seventeen comparative microarray analyses revealed 15 genes that were differentially (more than 200-fold) expressed in phenolics-rich versus phenolics-poor varieties. The results were validated by heterologous expression of the peroxidase FaPRX27 gene, which showed the highest altered expression level (more than 900-fold). The encoded protein was functionally characterized and is assumed to be involved in lignin formation during strawberry fruit ripening. Quantitative trait locus analysis indicated that the genomic region of FaPRX27 is associated with the fruit color trait. Down-regulation of the CHALCONE SYNTHASE gene and concomitant induction of FaPRX27 expression diverted the flux from anthocyanins to lignin. The results highlight the competition of the different phenolics pathways for their common precursors. The list of the 15 candidates provides new genes that are likely to impact polyphenol accumulation in strawberry fruit and could be used to develop molecular markers to select phenolics-rich germplasm.
Multimodal measurements of single-cell profiles are proving increasingly useful for characterizing cell states and regulatory mechanisms. In the present study, we developed PHAGE-ATAC (Assay for ...Transposase-Accessible Chromatin), a massively parallel droplet-based method that uses phage displaying, engineered, camelid single-domain antibodies ('nanobodies') for simultaneous single-cell measurements of protein levels and chromatin accessibility profiles, and mitochondrial DNA-based clonal tracing. We use PHAGE-ATAC for multimodal analysis in primary human immune cells, sample multiplexing, intracellular protein analysis and the detection of SARS-CoV-2 spike protein in human cell populations. Finally, we construct a synthetic high-complexity phage library for selection of antigen-specific nanobodies that bind cells of particular molecular profiles, opening an avenue for protein detection, cell characterization and screening with single-cell genomics.
Genomic alterations and expression of the p53 tumor suppressor gene and the epidermal growth factor receptor gene (EOFR) were investigated in 22 patients with primary World Health Organization (WHO) ...grade II gliomas that on recurrence had progressed to malignant gliomas of WHO grades III or IV. Mutations of the p53 gene (exons 5 to 8) were found in 12 of 22 primary tumors (10 of 13 astrocytomas, 1 of 7 oligodendrogliomas, 1 of 2 oligoastrocytomas). In each of these cases identical p53 mutations were present in the respective malignant recurrences. In all instances in which the p53 mutation was associated with p53 protein accumulation (10 of 12 cases) the percentage of p53 immunopositive tumor cells had increased from the primary to the recurrent tumor. None of the primary low-grade and none of the recurrent high-grade tumors (7 anaplastic astrocytomas, 10 anaplastic oligodendrogliomas, 4 anaplastic oligoastrocytomas, and 5 glioblastomas) showed evidence of EGFR gene amplification. Our results thus demonstrate that p53 is mutated in a high fraction of low-grade astrocytomas with progression to anaplastic astrocytomas and glioblastomas and that progression in such cases is frequently associated with an increase in the fraction of p53 immunopositive tumor cells. The general absence of EGFR amplification in our tumor series supports the hypothesis that the significance of p53 mutation and EGFR amplification may be different in glioblastomas that developed by progression from low-grade astrocytomas (secondary glioblastomas) compared to glioblastomas that developed rapidly in a de novo manner without a history of previous low-grade tumor (primary).
Background:
Dent disease is an X-linked tubulopathy frequently caused by mutations affecting the voltage-gated chloride channel and chloride/proton antiporter ClC-5. A recent study showed that ...defects in
OCRL1, encoding a phosphatidylinositol 4,5-bisphosphate 5-phosphatase (Ocrl) and usually found mutated in patients with Lowe syndrome, also can provoke a Dent-like phenotype (Dent 2 disease).
Methods:
We investigated 20
CLCN5-negative males from 17 families with a phenotype resembling Dent disease for defects in
OCRL1.
Results:
In our complete series of 35 families with a phenotype of Dent disease, a mutation in the
OCRL1 gene was detected in 6 kindreds. All were novel frameshift (Q70R
fsX88 and T121N
fsX122, detected twice) or missense mutations (I257T and R476W). None of our patients had cognitive or behavioral impairment or cataracts, 2 classic hallmarks of Lowe syndrome. All patients had mild increases in lactate dehydrogenase and/or creatine kinase levels, which rarely is observed in
CLCN5-positive patients, but frequently found in patients with Lowe syndrome. To explain the phenotypic heterogeneity caused by
OCRL1 mutations, we performed extensive data-bank mining and extended reverse-transcriptase polymerase chain reaction analysis, which provided no evidence for yet unknown (tissue-specific) alternative
OCRL1 transcripts.
Conclusion:
Mutations in the
OCRL1 gene are found in approximately 23% of kindreds with a Dent phenotype. Defective protein sorting/targeting of Ocrl might be the reason for mildly elevated creatine kinase and lactate dehydrogenase serum concentrations in these patients and a clue to suspect Dent disease unrelated to
CLCN5 mutations. It remains to be elucidated why the various
OCRL1 mutations found in patients with Dent 2 disease do not cause cataracts.
Epidemiologic evidence on contact allergy (CA) largely relies on clinical studies. However, the effects of the selection process until consultation as patient are largely unclear.
Prevalences of ...contact allergy to important allergens estimated from the population-based nested case–control study “KORA Allergy Study” in Augsburg, Germany (a subsample from the third MONICA survey in 1997/1998,
n
=
1141), were compared with proportions found in the Department of Dermatology of the Augsburg Municipal Hospital in patients of similar age patch tested between 1997 and 2000 (
n
=
555). Prevalences were standardized for sex, age, and atopic dermatitis as potential confounders.
Among the 25 substances tested, the fragrance mix (MONICA, estimated from the KORA Allergy Study: 11.4%, hospital: 12.9%) and nickel (MONICA: 9.9%, hospital: 12.9%) were the most common allergens. Larger differences between prevalences were noted particularly with ingredients of topicals used to treat varicose ulcers—a speciality of the Augsburg department, which is also reflected by comparing the department with the whole Information Network of (n =40) Departments of Dermatology (IVDK).
This locally matched comparison illustrates the differential effect of selection until presentation in dermatological departments.
Twenty primary central nervous system lymphomas (PCNSL) from immunocompetent patients (nineteen B‐cell lymphomas and one T‐cell lymphoma) were investigated for genetic alterations and/or expression ...of the genes BCL2, CCND1, CDK4, CDKN1A, CDKN2A, MDM2, MYC, RB1, REL, and TP53. The gene found to be altered most frequently was CDKN2A. Eight tumors (40%) showed homozygous and two tumors (10%) hemizygous CDKN2A deletions. Furthermore, methylation analysis of six PCNSL without homozygous CDKN2A loss revealed methylation of the CpG island within exon 1 of CDKN2A in three instances. Reverse transcription PCR analysis of CDKN2A mRNA expression was performed for 11 tumors and showed either no or weak signals. Similarly, immunocytochemistry for the CDKN2A gene product (p16) remained either completely negative or showed expression restricted to single tumor cells. None of the PCNSL showed amplification of CDK4. Similarly, investigation of CCND1 revealed no amplification, rearrangement or overexpression. The retinoblastoma protein was strongly expressed in all tumors. Only one PCNSL showed a mutation of the TP53 gene, i.e., a missense mutation at codon 248 (CGG to TGG: Arg to Trp). No evidence of BCL2 gene rearrangement was found in 11 tumors investigated. The bcl‐2 protein, however, was strongly expressed in most tumors. None of the 20 PCNSL demonstrated gene amplification of MDM2, MYC or REL. In summary, inactivation of CDKN2A by either homozygous deletion or DNA methylation represents an important molecular mechanism in PCNSL. Mutation of the TP53 gene and alterations of the other genes investigated appear to be of minor significance in these tumors.
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