Visualize the Distribution and Dynamics of Mitochondrial DNA (mtDNA) Nucleoids with Multiple Labeling Strategies.

Mitochondrial DNA (mtDNA) encodes a variety of rRNAs, tRNAs, and respiratory chain complex proteins. The integrity of mtDNA supports the mitochondrial functions and plays an essential role in numerous physiological and pathological processes. Mutations in mtDNA cause metabolic diseases and aging.

Rational design of self-assembled RNA nanostructures for HIV-1 virus assembly blockade.

Many pathological processes are driven by RNA-protein interactions, making such interactions promising targets for molecular interventions. HIV-1 assembly is one such process, in which the viral genomic RNA interacts with the viral Gag protein and serves as a scaffold to drive Gag multimerization that ultimately leads to formation of a virus particle. Here, we develop self-assembled RNA nanostructures that can inhibit HIV-1 virus assembly, achieved through hybridization of multiple artificial small RNAs with a stem-loop structure (STL) that we identify as a prominent ligand of Gag that can inhibit virus particle production via STL-Gag interactions.

ER-mitochondria contacts promote mtDNA nucleoids active transportation via mitochondrial dynamic tubulation.

A human cell contains hundreds to thousands of mitochondrial DNA (mtDNA) packaged into nucleoids. Currently, the segregation and allocation of nucleoids are thought to be passively determined by mitochondrial fusion and division. Here we provide evidence, using live-cell super-resolution imaging, that nucleoids can be actively transported via KIF5B-driven mitochondrial dynamic tubulation (MDT) activities that predominantly occur at the ER-mitochondria contact sites (EMCS).

Golgi-associated microtubules are fast cargo tracks and required for persistent cell migration.

Microtubules derived from the Golgi (Golgi MTs) have been implicated to play critical roles in persistent cell migration, but the underlying mechanisms remain elusive, partially due to the lack of direct observation of Golgi MT-dependent vesicular trafficking. Here, using super-resolution stochastic optical reconstruction microscopy (STORM), we discovered that post-Golgi cargos are more enriched on Golgi MTs and also surprisingly move much faster than on non-Golgi MTs. We found that, compared to non-Golgi MTs, Golgi MTs are morphologically more polarized toward the cell leading edge with significantly fewer inter-MT intersections.

Long-term dual-color tracking of genomic loci by modified sgRNAs of the CRISPR/Cas9 system.

Visualization of chromosomal dynamics is important for understanding many fundamental intra-nuclear processes. Efficient and reliable live-cell multicolor labeling of chromosomal loci can realize this goal. However, the current methods are constrained mainly by insufficient labeling throughput, efficiency, flexibility as well as photostability.