Biology subjects

Zhou, X.-Y.

Publications and source records attributed to Zhou, X.-Y..

4 recordsLinked to original sources

bioRxiv2024

Fish CDK2 recruits Dtx4 to degrade TBK1 through ubiquitination in the antiviral response

Although the classical biological protein cell cycle protein kinase CDK2 has been extensively studied in higher vertebrates, its function in lower vertebrates beyond the regulation of mitosis remains unknown. In this study, we report a distinct mechanism whereby IFN expression is negatively regulated in fish by CDK2. After infection with the spring viremia of carp virus (SVCV), fish CDK2 expression significantly increased in tissues and cells. Moreover, antiviral resistance was improved in cdk2-/- homozygotes, and the antiviral cytokine interferon (IFN) expression was significantly higher. At the cellular level, CDK2 overexpression reduced IFN expression, while cdk2 knockdown increased the ability of cells to produce IFN. Subsequently, it was discovered that fish CDK2 binds and degrades TBK1, resulting in reduced IFN. CDK2 increases the K48-linked ubiquitination of TBK1, causing its degradation, while E3 ubiquitin ligase Dtx4 was found to be involved in this process following the significant enhancement of TBK1 K48-linked ubiquitination. Protein mass spectrometry and immunoblot analysis confirmed that the K567 site on TBK1 is essential for CDK2 to engage with Dtx4 and degrade TBK1; thus, after mutating the K567 site, K48-linked ubiquitination of TBK1 was not enhanced by Dtx4, and TBK1 was not degraded by CDK2. Our data demonstrate that fish CDK2 recruits the E3 ubiquitin ligase Dtx4 to target the K567 site of TBK1 and promote its degradation. These results suggest that CDK2 in lower vertebrates is implicated in a specialized role for antiviral innate immunity.

immunology↗

bioRxiv2023

Microbiome Analysis of the Eastern Oyster As a Function of Ploidy and Seasons

Shellfish, such as the eastern oysters (Crassostrea virginica) are not only valued as seafood but also for the ecosystem services they provide, including improving water quality and reducing eutrophication. Excess N causes eutrophication, harmful algal blooms, fish kills and overall decline of estuarine ecosystems resulting in economic losses. Oyster reefs sequester N and enhance denitrification processes, however, information on the N cycling oyster microbiome is scarce with most studies focusing on random grab samples or on pathogens, such as Vibrio spp. Further, triploid oysters are often used for aquaculture, as they grow faster than diploids, but there is little information on potential microbiome differences with ploidy. To address these knowledge gaps, diploid and triploid farmed oysters were collected at monthly intervals over one year and analyzed using a coupled approach encompassing shotgun metagenomics and quantitative microbial elemental cycling (QMEC) qPCR assays. Overall, the genus Psychrobacter dominated the core microbiome across all samples, regardless of season or ploidy, followed by Synechococcus, Pseudomonas, Pseudoalteromonas and Clostridium. Psychrobacter abundances increased significantly in the colder months; the same trend was also observed in the alpha and beta diversity. However, warmer months had increased bacterial diversity relative to colder months. Gene functional profiles were similar among seasons and ploidy, with respiration and metabolism of carbohydrates, RNA, and proteins as dominant functions. There were strong positive correlations between abundance of the "core" microbiome taxa and gene functions associated with central metabolism, DNA and carbohydrate metabolism, strongly suggesting the functional role of Psychrobacter in the microbiome. Metagenome assembly was performed to characterize dominant species, followed by phylogenetic analysis of select MAGs (metagenome-assembled genomes), further supporting the presence of multiple Psychrobacter spp. Sequence-based identification of denitrification genes in the Pyschrobacter MAGs indicated the presence of norB, narH, narI, nirK, and norB. QMEC analysis indicated C and N cycling genes were most abundant, with no discernable patterns due to seasons or ploidy. Among N cycling genes, the nosZII clade was dominant, which is likely responsible for the eastern oysters potential for bioextraction and enhancing water quality via denitrification.

microbiology↗

bioRxiv2019

Dosage-sensitivity of human transcription factor genes

Changes in the copy number of protein-coding genes would lead to detrimental effects if the consequent changes in protein concentration disrupt essential cellular functions. Large-scale genomic studies have identified thousands of dosage-sensitive genes in human genome. We are interested in the dosage-sensitivity of transcription factor (TF) genes whose products are essential for the growth, division and differentiation of cells by regulating the expression of the genetic information encoded in the genome. We first surveyed the enrichment of human TF genes in four recently curated datasets of dosage-sensitive genes, including the haploinsufficient genes identified by a large-scale genomic study, the haploinsufficient genes predicted by a machine learning approach, the genes with conserved copy number across mammals, and the ohnologs. Then we selected the dosage-sensitive genes that are present in all the four dataset and regarded them as the most reliable dosage-sensitive genes, and the genes that are absent from any one of the four datasets as the most reliable dosage-insensitive genes, and surveyed the enrichments of TFs genes in these two datasets. A large number of TF genes were found to be dosage-insensitive, which is beyond the expectation based on the role of TFs. In spite of this, the likeness of TF genes to be dosage-sensitive were supported by five datasets, with the conserved-copy-number genes as the exception. The nuclear receptors are the only one family of TFs whose dosage-sensitivity was consistently supported by all the six datasets. In addition, we found that TF families with very few members are also more likely to be dosage-sensitive while the largest TF family, C2H2-ZF, are most likely dosage-insensitive. The most extensively studied TFs, p53, are not special in dosage-sensitivity. They are significantly enriched in only three datasets. We also confirmed that dosage-sensitive genes generally have long coding sequences, high expression levels and experienced stronger selective pressure. Our results indicate some TFs function in a dose-dependent manner while some other not. Gene dosage changes in some TF families like nuclear receptor would result in disease phenotypes while the effects of such changes in some TFs like C2H2-ZF would be mild.

genetics↗

bioRxiv2018

Desiccation Does Not Drastically Increase the Accessibility of Foreign DNA to the Nuclear Genomes: Evidence from the Frequency of Endosymbiotic DNA Transfer

Horizontal gene transfer (HGT) is a widely accepted force in the evolution of prokaryotic genomes. However, in eukaryotes, it is still in hot debate. Some bdelloid rotifers that are resistant to extreme desiccation and radiation were reported to have a very high level of HGTs. However, a similar report in another resistant invertebrate, tardigrades, has been mired in controversy. The DNA double-strand breaks (DSBs) induced by prolonged desiccation have been postulated to open the gateway of nuclear genome for foreign DNA integration and thus facilitate the HGT process. If so, the rate of endosymbiotic DNA transfer should also be enhanced. We first surveyed the abundance of nuclear mitochondrial DNAs (NUMTs) and nuclear plastid DNAs (NUPTs) in three groups of eukaryotes that are extremely resistant to desiccation, bdelloid rotifers, A. vaga and A. ricciae, tardigrades, H. dujardini and R. varieornatus, and the resurrection plants, D. hygrometricum and S. tamariscina. Excessive NUMTs or NUPTs have not been detected. Furthermore, we compared nine groups of desiccation-tolerant organisms with their desiccation-sensitive relatives but did not find significant difference in the NUMT/NUPT contents. Desiccation could induce DSBs, but it unlikely dramatically increase the frequency of foreign sequence integration in most eukaryotes. Only in the nuclear genomes enriched in repetitive sequences, the DSBs are predominantly repaired by non-homologous end joining (NHEJ) and desiccation-induced DSBs is possible to enhance the integration of foreign sequences into nuclear genome for some degree.

evolutionary biology↗