Biology subjects

Tang, H.-W.

Publications and source records attributed to Tang, H.-W..

4 recordsLinked to original sources

bioRxiv2024

FOXO-regulated Deaf1 controls muscle regeneration through autophagy

The commonality between various muscle diseases is the loss of muscle mass, function, and regeneration, which severely restricts mobility and impairs the quality of life. With muscle stem cells (MuSCs) playing a key role in facilitating muscle repair, targeting regulators of muscle regeneration has been shown to be a promising therapeutic approach to repair muscles. However, the underlying molecular mechanisms driving muscle regeneration are complex and poorly understood. Here, we identified a new regulator of muscle regeneration, Deformed epidermal autoregulatory factor 1 (Deaf1) - a transcriptional factor downstream of FOXO signaling. We showed that Deaf1 is transcriptionally repressed by FOXOs and that Deaf1 targets to PI3KC3 and Atg16l1 promoter regions and suppresses their expressions. Deaf1 depletion therefore induces autophagy, which in turn blocks MuSC survival and differentiation. In contrast, Deaf1 overexpression inactivates autophagy in MuSCs, leading to increased protein aggregation and cell death. Interestingly, Deaf1 depletion and overexpression both lead to defects in muscle regeneration, highlighting the importance of fine tuning Deaf1-regulated autophagy during muscle regeneration. We further showed that Deaf1 expression is altered in aging and cachectic MuSCs. Remarkably, manipulation of Deaf1 expression can attenuate muscle atrophy and restore muscle regeneration in aged mice or mice with cachectic cancers. Together, our findings unveil an evolutionarily conserved role for Deaf1 in muscle regeneration, providing insights into the development of new therapeutic strategies against muscle atrophy.

cell biology↗

bioRxiv2022

Next-generation large-scale binary protein interaction network for Drosophila

Generating reference maps of the interactome networks underlying most cellular functions can greatly illuminate genetic studies by providing a protein-centric approach to finding new components of existing pathways, complexes, and processes. Here, we applied state-of-the-art experimental and bioinformatics methods to identify high-confidence binary protein-protein interactions (PPIs) for Drosophila melanogaster. We performed four all-by-all yeast two-hybrid (Y2H) screens of >10,000 Drosophila proteins, resulting in the FlyBi dataset of 8,723 PPIs among 2,939 proteins. As part of this effort, we tested subsets of our data and data from previous PPI datasets using an orthogonal assay, which allowed us to normalize data quality across datasets. Next, we integrated our FlyBi data with previous PPI data, resulting in an expanded, high-confidence binary Drosophila reference interaction network, DroRI, comprising 17,232 interactions among 6,511 proteins. These data are accessible through the Molecular Interaction Search Tool (MIST) and other databases. To assess the utility of the PPI resource, we used novel interactions from the FlyBi dataset to generate an autophagy interaction network that we validated in vivo using two different autophagy-related assays. We found that deformed wings (dwg) encodes a protein that is both a regulator and a target of autophagy. Altogether, the resources generated in this project provide a strong foundation for building high-confidence new hypotheses regarding protein networks and function.

cell biology↗

bioRxiv2020

CG14906 (mettl4) mediates m6A methylation of U2 snRNA in Drosophila

Recent studies reported that METTL4 regulates DNA 6mA in vivo and therefore is a candidate DNA m6A methyltransfease. However, the enzymatic activity of METTL4 in vitro has not been demonstrated in part due to the difficulties of obtaining well-folded proteins. Here we show that mettl4 is a major methyltransfase responsible for m6A methylation of U2 snRNA both in vitro and in vivo in fly, and identify adenosine at 29th position as the site of m6A methylation. This study answered a long-standing question regarding the enzymatic activity of METTL4, and thus paved the way for further investigating the functions of METTL4 in different biological settings.

biochemistry↗

bioRxiv2020

Lipid-specific labeling of enveloped viruses with quantum dots for single-virus tracking

Quantum dots (QDs) possess optical properties of superbright fluorescence, excellent photostability, narrow emission spectra, and optional colors. Labeled with QDs, single molecules/viruses can be rapidly and continuously imaged for a long time, providing more detailed information than labeled with other fluorophores. While they are widely used to label proteins in single-molecule tracking studies, QDs have rarely been used to study virus infection, mainly due to lack of accepted labeling strategies. Here, we report a general method to mildly and readily label enveloped viruses with QDs. Lipid-biotin conjugates were used to recognize and mark viral lipid membranes, and streptavidin (SA)-QD conjugates were used to light them up. Such a method allowed enveloped viruses to be labeled in 2 hours with specificity and efficiency up to 99% and 98%. The intact morphology and the native infectivity of viruses could be furthest preserved. With the aid of this QD labeling method, we lit wild-type (WT) and mutant Japanese encephalitis virus (JEV) up, tracked their infection in living Vero cells, and found that H144A and Q258A substitutions in the envelope (E) protein didnt affect the virus intracellular trafficking. The lipid-specific QD labeling method described in this study provides a handy and practical tool to readily "see" the viruses and follow their infection, facilitating the widespread use of single-virus tracking and the uncovering of complex infection mechanisms. Author summaryVirus infection in host cells is a complex process comprising a large number of dynamic molecular events. Single-virus tracking is a versatile technique to study these events. To perform this technique, viruses must be fluorescently labeled to be visible to fluorescence microscopes. Quantum dot is a kind of fluorescent tags that has many unique optical properties. It has been widely used to label proteins in single-molecule tracking studies, but rarely used to study virus infection, mainly due to lack of accepted labeling method. In this study, we developed a lipid-specific method to readily, mildly, specifically, and efficiently label enveloped viruses with quantum dots by recognizing viral envelope lipids with lipid-biotin conjugates and recognizing these lipid-biotin conjugates with streptavidin-quantum dot conjugates. Such a method is superior to the commonly used DiD/DiO labeling and the other QD labeling methods. It is not only applicable to normal viruses, but also competent to label the key protein-mutated viruses and the inactivated high virulent viruses, providing a powerful tool for single-virus tracking.

biochemistry↗