Distinct GSDMB protein isoforms and protease cleavage processes differentially control pyroptotic cell death and mitochondrial damage in cancer cells.

Gasdermin (GSDM)-mediated pyroptosis is functionally involved in multiple diseases, but Gasdermin-B (GSDMB) exhibit cell death-dependent and independent activities in several pathologies including cancer. When the GSDMB pore-forming N-terminal domain is released by Granzyme-A cleavage, it provokes cancer cell death, but uncleaved GSDMB promotes multiple pro-tumoral effects (invasion, metastasis, and drug resistance). To uncover the mechanisms of GSDMB pyroptosis, here we determined the GSDMB regions essential for cell death and described for the first time a differential role of the four translated GSDMB isoforms (GSDMB1-4, that differ in the alternative usage of exons 6-7) in this process.

A simple, quick, and efficient CRISPR/Cas9 genome editing method for human induced pluripotent stem cells.

Induced pluripotent stem cells (iPSCs) have become an essential research platform to study different human diseases once being discovered by Dr. Shinya Yamanaka in 2006. Another breakthrough in biomedical research is the application of CRISPR/Cas9 system for genome editing in mammalian cells.

A versatile single-plasmid system for tissue-specific and inducible control of gene expression in transgenic mice.

We describe a novel transgenic system for tissue-specific and inducible control of gene expression in mice. The system employs a tetracycline-responsive CMV promoter that controls transcription of a short-hairpin RNA (shRNA) that remains nonfunctional until an interrupting reporter cassette is excised by Cre recombinase. Insertion of Dicer and Drosha RNase processing sites within the shRNA allows generation of siRNA to knock down a target gene efficiently.

Polymerase transcriptase release factor (PTRF) anchors MG53 protein to cell injury site for initiation of membrane repair.

Plasma membrane repair is an essential process for maintenance of homeostasis at the cellular and tissue levels, whereas compromised repair capacity contributes to degenerative human diseases. Our recent studies show that MG53 is essential for muscle membrane repair, and defects in MG53 function are linked to muscular dystrophy and cardiac dysfunction. Here we report that polymerase I and transcript release factor (PTRF), a gene known to regulate caveolae membrane structure, is an indispensable component of the membrane repair machinery.

Amphipathic tail-anchoring peptide and Bcl-2 homology domain-3 (BH3) peptides from Bcl-2 family proteins induce apoptosis through different mechanisms.

Bcl-2 homology domain-3 (BH3) peptides are potent cancer therapeutic reagents that target regulators of apoptotic cell death in cancer cells. However, their cytotoxic effects are affected by different expression levels of Bcl-2 family proteins. We recently found that the amphipathic tail-anchoring peptide (ATAP) from Bfl-1, a bifunctional Bcl-2 family member, produced strong pro-apoptotic activity by permeabilizing the mitochondrial outer membrane.

The tail-anchoring domain of Bfl1 and HCCS1 targets mitochondrial membrane permeability to induce apoptosis.

Many Bcl2 family proteins target intracellular membranes by their C-terminal tail-anchor domain. Bfl1 is a bi-functional Bcl2 family protein with both anti- and pro-apoptotic activities and contains an amphipathic tail-anchoring peptide (ATAP; residues 147-175) with unique properties. Here we show that ATAP targets specifically to mitochondria, and induces caspase-dependent apoptosis that does not require Bax or Bak.

Regulation of Aurora-A kinase gene expression via GABP recruitment of TRAP220/MED1.

The TRAP/Mediator coactivator complex serves as a functional interface between DNA-bound transactivators and the RNA polymerase II-associated basal transcription apparatus. TRAP220/MED1 is a variably associated subunit of the complex that plays a specialized role in selectively targeting TRAP/Mediator to specific genes. Ablation of the Trap220/Med1 gene in mice impairs embryonic cell growth, yet the underlying mechanism is unknown.

Transcriptional regulation of TNF family receptors and Bcl-2 family by chemotherapeutic agents in murine CT26 cells.

Various chemotherapeutic agents have been shown to sensitize cancer cells to members of the tumor necrosis factor (TNF) family. However, it is unclear whether sensitization by chemotherapeutic agents involves the transcriptional regulation of apoptosis-related genes. In this study, we investigated mRNA regulation of TNF family receptors and Bcl-2 family members after treating the murine colon cancer cell line, CT26, with various apoptosis inducers.

Conversion of Bfl-1, an anti-apoptotic Bcl-2 family protein, to a potent pro-apoptotic protein by fusion with green fluorescent protein (GFP).

Human Bfl-1 is an anti-apoptotic Bcl-2 family member. Here, we found that Bfl-1 was converted into a potent death-promoting protein by green fluorescent protein (GFP) fusion with its N-terminus. The transient expression of GFP-Bfl-1 induced cytochrome c release and triggered apoptosis in 293T cells, which depended on the mitochondrial localization of GFP-Bfl-1.