Genes to Cells最新文献

Transducer of ErbB2 (TOB) proteins have been shown to promote mRNA decay through interactions with the CCR4–NOT complex and poly(A)-binding protein (PABP). While their role in deadenylation-mediated mRNA degradation is well established, their potential function in translational control remains to be elucidated. Here, we employed an in vitro translation system combined with an RNA tethering strategy to examine the function of TOB1 and TOB2 in translation. Our results demonstrate that TOB1 and TOB2 act as repressors of translation initiation, independent of deadenylation. Notably, this translational repression selectively targets eIF4A-dependent translation, while translation driven by eIF4A-independent IRES elements remains unaffected. While the interaction between TOB proteins and PABP appears to be dispensable, as disruption of this interaction only partially reduces translational repression, the knockdown of CNOT1, the scaffold of the CCR4–NOT complex, substantially relieves this repression, highlighting its indispensable role in the mechanism. Collectively, our findings uncover a previously unrecognized function of TOB proteins as direct repressors of translation initiation, independent of mRNA decay, and highlight a specific reliance on eIF4A activity and CCR4–NOT complex integrity.

The tumor microenvironment strongly influences cancer cell behavior, including growth, migration, invasiveness, and gene expression dynamics. Adhesion G protein-coupled receptors (aGPCR) play critical roles in cell–cell or cell-extracellular matrix (ECM) interaction. This study aims to investigate the functions and elucidate signaling of Latrophilin-2 (LPHN2), an aGPCR, in breast cancer progression using MDA-MB-231 cells. LPHN2-deficient MDA-MB-231 cells exhibited decreased invasion-like sphere structure in 3D culture, reduced proliferation, diminished adhesion to collagen I, and impaired migration activity. Reporter assays and pharmacological inhibition experiments revealed that the C-terminal fragment (CTF) of LPHN2 activates SRE- and CREB-mediated gene transcription while activating ROCK and PKA signaling pathways. Additionally, downregulation of Gα12/13 and Gαs reduced cell migration in both wild-type and CTF-overexpressing LPHN2-knockout cells, demonstrating that LPHN2 couples to Gα12/13 and Gαs signaling pathways. These findings highlight the functional significance of LPHN2 in breast cancer cell behavior and provide potential therapeutic targets for breast cancer intervention.

Long noncoding RNAs (lncRNAs) are involved in various biological events. Previously we reported that lncRNA CCDC26 controls myeloid leukemia cell proliferation and mortality by regulating the proto-oncogene KIT. However, the mechanism of lncRNA CCDC26 effects on carcinogenesis and cell differentiation remains unclarified. To investigate the mechanism of lncRNA CCDC26 activity, we analyzed its protein partners using the S1 aptamer/cross-linking-immunoprecipitation (S1-CLIP) experiment. We identified a cytoskeleton protein (vimentin), chromatin proteins (chromobox 1/5 transcription factors [CBX1 and CBX5]) and a nuclear splicing-related protein heterogeneous nuclear ribonucleoprotein C (HNRNPC) as its interaction partners. As lncRNA CCDC26 is ubiquitously present in the cell (in cytoplasm, nucleoplasm, and chromatin cellular fractions); these results evidence that lncRNA CCDC26 is a unique multifunctional lncRNA that functions by interacting with several proteins in multiple intracellular compartments. We further identified the sequence through which it interacts with proteins by using a series of truncated-lncRNA CCDC26 fragments and RNA immunoprecipitation (RIP) experiments. Furthermore, using RIP, we identified the vimentin domain required for the lncRNA CCDC26 binding. Notably, CCDC26 knockdown reduced CBX1/CBX5 binding at certain gene promoters, correlating with increased gene expression. These findings suggest that CCDC26 may regulate transcription by interacting with CBX1 and CBX5.

Interferon-gamma (IFNγ) plays a crucial role in the pathogenesis of type 1 diabetes (T1D) and is widely utilized to license mesenchymal stem/stromal cells (MSCs) to enhance their immunosuppressive properties through a process known as preconditioning or priming. This study investigates the interaction of MSCs preconditioned with (IFNγ⁺) or without (IFNγ⁻) IFNγ, with peripheral blood mononuclear cells (PBMCs) from healthy controls (HC) and T1D patients. We assessed the effects of these interactions on anti-inflammatory gene expression, chemokine and receptor profiles, and the induction of regulatory T (Treg) cells. Our findings reveal contrasting responses in HC and T1D PBMCs when exposed to IFNγ⁺ and IFNγ⁻ MSCs, particularly in the expression of key genes such as CXCR3 and its ligands (CXCL9, CXCL10), CXCR6, CCR5, and its ligands (CCL3 and CCL4). Pathway enrichment analysis further showed that IFNγ preconditioning tailors MSC responses to specific immune microenvironments. These differential gene expression patterns were also reflected in the proportions of Treg cells, which varied depending on whether paracrine signaling or direct cell contact was involved. Collectively, our results demonstrate that IFNγ⁺ and IFNγ⁻ MSCs create distinct immunomodulatory microenvironments in T1D PBMCs compared to HC PBMCs, emphasizing the potential for tailored MSC-based therapies in T1D treatment.

The fission yeast Schizosaccharomyces pombe is a valuable unicellular model organism that proliferates predominantly in the haploid state. Under nitrogen starvation, sexual reproduction occurs, resulting in the formation of a diploid zygote and subsequent meiosis, producing four haploid ascospores. The genetic tractability of yeast, particularly, its ability to produce offspring through sexual reproduction, makes it a widely used model organism. Spores also serve as a model for dormant cells. In this study, I present a highly efficient and low-cost method for purifying S. pombe spores using an aqueous two-phase system (ATPS). Using polyethylene glycol (PEG)-salt (e.g., phosphate)-based ATPS, free spores were found to partition exclusively into the upper (PEG-rich) phase. In contrast, spores lacking Isp3, which forms the outermost spore wall layer, partitioned into the lower (salt-rich) phase, like vegetative cells. This suggests that the Isp3 layer imparts hydrophobicity to the spore surface, facilitating efficient separation in ATPS. This unique surface property may also reflect differences in ecological adaptation and spore dispersal strategies between S. pombe and other fission yeast species.