Publications by authors named "Yuval Malka"

Prolonged exposure to interferon-gamma (IFNγ) and the associated increased expression of the enzyme indoleamine 2,3-dioxygenase 1 (IDO1) create an intracellular shortage of tryptophan in the cancer cells, which stimulates ribosomal frameshifting and tryptophan to phenylalanine (W>F) codon reassignments during protein synthesis. Here, we investigated whether such neoepitopes can be useful targets of adoptive T cell therapy. Immunopeptidomic analyses uncovered hundreds of W>F neoepitopes mainly presented by the HLA-A24:02 allele.

View Article and Find Full Text PDF

Messenger RNA (mRNA) translation is a tightly controlled process frequently deregulated in cancer. Key to this deregulation are transfer RNAs (tRNAs), whose expression, processing and post-transcriptional modifications are often altered in cancer to support cellular transformation. In conditions of limiting levels of amino acids, this deregulated control of protein synthesis leads to aberrant protein production in the form of ribosomal frameshifting or misincorporation of non-cognate amino acids.

View Article and Find Full Text PDF

Inflammatory cytokines are pivotal to immune responses. Upon cytokine exposure, cells enter an "alert state" that enhances their visibility to the immune system. Here, we identified an alert-state subpopulation of ribosomes defined by the presence of the P-stalk.

View Article and Find Full Text PDF
Article Synopsis
  • Human cells can trigger a form of programmed cell death (apoptosis) when faced with DNA damage, primarily through the activation of the p53 protein.
  • Interestingly, even cells without p53 can still undergo apoptosis, which seems to be linked to issues with protein translation, specifically ribosomes stalling on rare codons and reduced translation initiation.
  • A genetic study revealed that the tRNAse SLFN11 and the kinase GCN2 are crucial for this stalling and subsequent stress signaling, which leads to apoptosis, offering insights into chemotherapy resistance in certain tumors where SLFN11 is often inactive.
View Article and Find Full Text PDF

Genes limiting T cell antitumor activity may serve as therapeutic targets. It has not been systematically studied whether there are regulators that uniquely or broadly contribute to T cell fitness. We perform genome-scale CRISPR-Cas9 knockout screens in primary CD8 T cells to uncover genes negatively impacting fitness upon three modes of stimulation: (1) intense, triggering activation-induced cell death (AICD); (2) acute, triggering expansion; (3) chronic, causing dysfunction.

View Article and Find Full Text PDF

Targeting the PI3K-AKT-mTOR pathway is a promising therapeutic strategy for breast cancer treatment. However, low response rates and development of resistance to PI3K-AKT-mTOR inhibitors remain major clinical challenges. Here, we show that MYC activation drives resistance to mTOR inhibitors (mTORi) in breast cancer.

View Article and Find Full Text PDF

The use of alternative promoters, splicing, and cleavage and polyadenylation (APA) generates mRNA isoforms that expand the diversity and complexity of the transcriptome. Here, we uncovered thousands of previously undescribed 5' uncapped and polyadenylated transcripts (5' UPTs). We show that these transcripts resist exonucleases due to a highly structured RNA and N6-methyladenosine modification at their 5' termini.

View Article and Find Full Text PDF

The majority of mammalian genes contain one or more alternative polyadenylation sites. Choice of polyadenylation sites was suggested as one of the underlying mechanisms for generating longer/shorter transcript isoforms. Here, we demonstrate that mature mRNA transcripts can undergo additional cleavage and polyadenylation at a proximal internal site in the 3'-UTR, resulting in two stable, autonomous, RNA fragments: a coding sequence with a shorter 3'-UTR (body) and an uncapped 3'-UTR sequence downstream of the cleavage point (tail).

View Article and Find Full Text PDF

Most organisms use 24-hr circadian clocks to keep temporal order and anticipate daily environmental changes. In Drosophila melanogaster CLOCK (CLK) and CYCLE (CYC) initiates the circadian system by promoting rhythmic transcription of hundreds of genes. However, it is still not clear whether high amplitude transcriptional oscillations are essential for circadian timekeeping.

View Article and Find Full Text PDF