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Good, C. R.

Publications and source records attributed to Good, C. R..

4 recordsLinked to original sources

Expanding the HIF-2α proteomic interactome with TurboID proximity labeling.

The transcription factor HIF2 is a central regulator of cellular adaptation to hypoxia, orchestrating gene expression programs that control angiogenesis, erythropoiesis, and metabolic reprogramming, and is famously overexpressed in cancers such as clear cell Renal Cell Carcinoma (ccRCC). While the gene targets of HIF2 have been extensively characterized, the composition and dynamics of its protein interaction network remain less well defined. In this study, we sought to systematically characterize proteins associated with HIF2 using two distinct proteomic approaches, enabling the identification of both stable binding partners and transient or indirect interactors. We integrated affinity purification mass spectrometry with proximity labeling strategies, thus expanding the existing interactome of HIF2 to include uniquely identified proteins and complexes such as members of the nuclear pore complex. Across both immunoprecipitation mass spectrometry (IP MS) and TurboID MS, we identified 888 and 1,048 proteins, respectively. We applied stringent filtering criteria to refine both datatsets, yielding a dataset of 329 HIF2 interacting proteins, approximately 75% of which have yet to be documented as HIF2 interactors. We queried this set across publicly available cancer genomics and proteomics datasets and detected expression of our interactors in breast cancer and ccRCC tumor proteomes. These findings led us to identify GRHL2 and KIF4A as proteomic interactors that contribute to poor patient survival in breast cancer. Taken together, we herein provide a comprehensive resource of HIF2 interacting proteins which provide insights into the mechanisms by which HIF2 drives disease progression.

biochemistry↗

Deciphering the role of histone modifications in memory and exhausted CD8 T cells

Exhausted CD8 T cells (TEX) arising during chronic infections and cancer have reduced functional capacity and limited fate flexibility that prevents optimal disease control and response to immunotherapies. Compared to memory (TMEM) cells, TEX have a unique open chromatin landscape underlying a distinct gene expression program. How TEX transcriptional and epigenetic landscapes are regulated through histone post-translational modifications (hPTMs) remains unclear. Here, we profiled key activating (H3K27ac and H3K4me3) and repressive (H3K27me3 and H3K9me3) histone modifications in naive CD8 T cells (TN), TMEM and TEX. We identified H3K27ac-associated super-enhancers that distinguish TN, TMEM and TEX, along with key transcription factor networks predicted to regulate these different transcriptional landscapes. Promoters of some key genes were poised in TN, but activated in TMEM or TEX whereas other genes poised in TN were repressed in TMEM or TEX, indicating that both repression and activation of poised genes may enforce these distinct cell states. Moreover, narrow peaks of repressive H3K9me3 were associated with increased gene expression in TEX, suggesting an atypical role for this modification. These data indicate that beyond chromatin accessibility, hPTMs differentially regulate specific gene expression programs of TEX compared to TMEM through both activating and repressive pathways.

immunology↗

Histone acetylation in an Alzheimer's disease cell model promotes homeostatic amyloid-reducing pathways

Alzheimers Disease (AD) is a disorder characterized by cognitive decline, neurodegeneration, and accumulation of amyloid plaques and tau neurofibrillary tangles in the brain. Dysregulation of epigenetic histone modifications may lead to expression of transcriptional programs that play a role either in protecting against disease genesis or in worsening of disease pathology. One such histone modification, acetylation of histone H3 lysine residue 27 (H3K27ac), is primarily localized to genomic enhancer regions and promotes active gene transcription. We previously discovered H3K27ac to be more abundant in AD patient brain tissue compared to the brains of age-matched non-demented controls. In this study, we use iPSC-neurons derived from familial AD patients with an amyloid precursor protein (APP) duplication (APPDup neurons) as a model to study the functional effect of lowering CBP/P300 enzymes that catalyze H3K27ac primarily at gene enhancers. We found that homeostatic amyloid-reducing genes were upregulated in the APPDup neurons compared to non- demented controls. We lowered CBP/P300 to reduce H3K27ac, which led to decreased expression of numerous of these homeostatic amyloid-reducing genes, along with increased extracellular secretion of a toxic amyloid-{beta} species, A{beta}(1-42). Our findings suggest that epigenomic histone acetylation, including H3K27ac, drives expression of compensatory genetic programs in response to AD-associated insults, specifically those resulting from APP duplication, and thus may play a role in mitigating AD pathology in neurons.

neuroscience↗

Impaired tumor death receptor signaling drives resistance to CAR T cell therapy

Cellular immunotherapy using T cells engineered to express chimeric antigen receptors targeting CD19 (CART19) leads to long-term remission in patients with B-cell malignancies1-5. Unfortunately, a significant fraction of patients demonstrate primary resistance to CART19 or experience relapse after achieving remission. Beyond loss of target antigen, the molecular pathways governing CART19 failure are unknown. Here we demonstrate that death receptors, cell surface signaling molecules that induce target cell apoptosis, are key mediators of leukemic resistance and CART19 failure. Using a functional CRISPR/Cas9-based genome-wide knockout screen6 in B-cell acute lymphoblastic leukemia (ALL), we identified the death receptor signaling pathway as a central regulator of sensitivity to CART19-induced cell death. In the absence of the pro-apoptotic death receptor signaling molecules BID or FADD, ALL cells were resistant to CART19 cytotoxicity, resulting in rapid disease progression in mice. We found that this initial resistance to cytotoxicity led to persistence of tumor cells, which drove the development of T cell dysfunction that further compromised anti-tumor immunity and permitted tumor outgrowth. We validated these findings using clinical samples collected from patients with ALL treated with CD19-targeted CAR T cells and found that expression of pro-apoptotic death receptor pathway genes in pre-treatment tumor samples correlated with CAR T cell expansion and persistence, as well as patient response and overall survival. Our findings indicate that tumor-intrinsic death receptor signaling directly contributes to CAR T cell failure.

immunology↗