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Biology subjects

Chen, S.-L.

Publications and source records attributed to Chen, S.-L..

3 recordsLinked to original sources

Nuclear receptor interaction protein (NRIP) as a novel actin-binding protein involved in invadosome formation for myoblast fusion

To investigate the role of nuclear receptor interaction protein (NRIP) in myoblast fusion, both the primary myoblasts from muscle-specific NRIP-knockout mice and NRIP-null C2C12 cells (KO19 cells) exhibited a significant deficit in the fusion index during myogenesis; on the other hand, overexpressed NRIP in KO19 cells could rescue myotube formation. Furthermore, NRIP was found to interact with actin directly and reciprocally that is an invadosome component for myoblast fusion. Endogenous NRIP colocalized with components of invadosome such as F-actin, Tks5, and cortactin at the tips of cells during C2C12 differentiation, and exogenous NRIP was enriched with actin at the tip of attacking cells during myogenic fusion, implying that NRIP is a novel invadosome component. Using time-lapse microscopy and cell-cell fusion assays further confirmed NRIP directly participates in cell fusion through actin. Moreover, to map the domain of NRIP-actin binding, NRIP interacted with actin either through WD40 domains directly for binding or indirectly through the IQ domain for -actinin 2 binding with actin. NRIP with actin binding was strongly correlated with invadosome formation and myotube fusion. Collectively, NRIP acts as a novel actin-binding protein through its WD40 or the IQ to form invadosomes that trigger myoblast fusion.

cell biology↗

The origin and underlying driving forces of the SARS-CoV-2 outbreak

The spread of SARS-CoV-2 since December 2019 has become a pandemic and impacted many aspects of human society. Here, we analyzed genetic variation of SARS-CoV-2 and its related coronavirus and found the evidence of intergenomic recombination. After correction for mutational bias, analysis of 137 SARS-CoV-2 genomes as of 2/23/2020 revealed the excess of low frequency mutations on both synonymous and nonsynonymous sites which is consistent with recent origin of the virus. In contrast to adaptive evolution previously reported for SARS-CoV in its brief epidemic in 2003, our analysis of SARS-CoV-2 genomes shows signs of relaxation of selection. The sequence similarity of the spike receptor binding domain between SARS-CoV-2 and a sequence from pangolin is probably due to an ancient intergenomic introgression. Therefore, SARS-CoV-2 might have cryptically circulated within humans for years before being recently noticed. Data from the early outbreak and hospital archives are needed to trace its evolutionary path and reveal critical steps required for effective spreading. Two mutations, 84S in orf8 protein and 251V in orf3 protein, occurred coincidentally with human intervention. The 84S first appeared on 1/5/2020 and reached a plateau around 1/23/2020, the lockdown of Wuhan. 251V emerged on 1/21/2020 and rapidly increased its frequency. Thus, the roles of these mutations on infectivity need to be elucidated. Genetic diversity of SARS-CoV-2 collected from China was two time higher than those derived from the rest of the world. In addition, in network analysis, haplotypes collected from Wuhan city were at interior and have more mutational connections, both of which are consistent with the observation that the outbreak of cov-19 was originated from China. SUMMARYIn contrast to adaptive evolution previously reported for SARS-CoV in its brief epidemic, our analysis of SARS-CoV-2 genomes shows signs of relaxation of selection. The sequence similarity of the spike receptor binding domain between SARS-CoV-2 and a sequence from pangolin is probably due to an ancient intergenomic introgression. Therefore, SARS-CoV-2 might have cryptically circulated within humans for years before being recently noticed. Data from the early outbreak and hospital archives are needed to trace its evolutionary path and reveal critical steps required for effective spreading. Two mutations, 84S in orf8 protein and 251V in orf3 protein, occurred coincidentally with human intervention. The 84S first appeared on 1/5/2020 and reached a plateau around 1/23/2020, the lockdown of Wuhan. 251V emerged on 1/21/2020 and rapidly increased its frequency. Thus, the roles of these mutations on infectivity need to be elucidated.

evolutionary biology↗

A GYS2/p53 negative feedback loop restricts tumor growth in HBV-related hepatocellular carcinoma

Hepatocarcinogenesis is attributed to the reprogramming of cellular metabolism as consequence of the alteration in metabolite-related gene regulation. Identifying the mechanism of aberrant metabolism is of great potential to provide novel targets for the treatment of hepatocellular carcinoma (HCC). Here, we demonstrated that glycogen synthase 2 (GYS2) restricted tumor growth in HBV-related HCC via a negative feedback loop with p53. Expression of GYS2 was significantly downregulated in HCC and correlated with decreased glycogen content and unfavorable patient outcomes. GYS2 overexpression suppressed, whereas GYS2 knockdown facilitated cell proliferation in vitro and tumor growth in vivo via modulating p53 expression. GYS2 competitively bound to MDM2 to prevent p53 from MDM2-mediated ubiquitination and degradation. Furthermore, GYS2 enhanced the p300-induced acetylation of p53 at K373/382, which in turn inhibited the transcription of GYS2 in the support of HBx/HDAC1 complex. In summary, our findings suggest that GYS2 serves as a prognostic factor and functions as a tumor suppressor in HCC. The newly identified HBx/GYS2/p53 axis is responsible for the deregulation of glycogen metabolism and represents a promising therapeutic target for the clinical management of HCC.\n\nSynopsisThis study elucidate the role of GYS2 in glycogen metabolism and the progression of HCC. The newly identified HBx/GYS2/p53 axis is responsible for the deregulation of glycogen metabolism and represents a promising therapeutic target for the clinical management of HCC.\n\nO_LIDecrease of GYS2 was significantly correlated with decreased glycogen content and unfavorable patient outcomes in a large cohort containing 768 patients with HCC.\nC_LIO_LIGYS2 overexpression suppressed, whereas GYS2 knockdown facilitated cell proliferation in vitro and tumor growth in vivo via modulating p53 signaling pathway.\nC_LIO_LIGYS2 competitively bound to MDM2 to prevent p53 from MDM2-mediated ubiquitination and degradation.\nC_LIO_LIGYS2 enhanced the p300-induced acetylation of p53 at Lys373/382, which in turn inhibited the transcription of GYS2 in the support of HBx/HDAC1 complex.\nC_LI

pathology↗