Publications by authors named "Kristine A Keon"

Background: Cardiogenic shock (CS) is associated with high in-hospital mortality. Objective assessment of its severity and prognosis is paramount for timely therapeutic interventions. This study aimed to evaluate the efficacy of the shock index (SI) and its variants as prognostic indicators for in-hospital mortality.

View Article and Find Full Text PDF

We used the Legionella pneumophila effector SidK to affinity purify the endogenous vacuolar-type ATPases (V-ATPases) from lemon fruit. The preparation was sufficient for cryoelectron microscopy, allowing structure determination of the enzyme in two rotational states. The structure defines the ATP:H ratio of the enzyme, demonstrating that it can establish a maximum ΔpH of ∼3, which is insufficient to maintain the low pH observed in the vacuoles of juice sac cells in lemons and other citrus fruit.

View Article and Find Full Text PDF

V-ATPases are rotary proton pumps that serve as signaling hubs with numerous protein binding partners. CryoEM with exhaustive focused classification allowed detection of endogenous proteins associated with porcine kidney V-ATPase. An extra C subunit was found in ∼3% of complexes, whereas ∼1.

View Article and Find Full Text PDF

Macroautophagy/autophagy is the process of self-digestion through the lysosomes; it disassembles unnecessary or dysfunctional long-lived proteins and damaged organelles for the recycling of biomacromolecules. Unfortunately, cancer cells can hijack this mechanism to survive under metabolic stress or develop drug resistance during chemotherapy. Increasing evidence indicates that the combination of autophagy inhibition and chemotherapy is a promising cancer treatment strategy.

View Article and Find Full Text PDF

Vacuolar-type ATPases (V-ATPases) are rotary enzymes that acidify intracellular compartments in eukaryotic cells. These multi-subunit complexes consist of a cytoplasmic V region that hydrolyzes ATP and a membrane-embedded V region that transports protons. V-ATPase activity is regulated by reversible dissociation of the two regions, with the isolated V and V complexes becoming autoinhibited on disassembly and subunit C subsequently detaching from V.

View Article and Find Full Text PDF

Vacuolar-type adenosine triphosphatases (V-ATPases) are proton pumps found in almost all eukaryotic cells. These enzymes consist of a soluble catalytic V region that hydrolyzes ATP and a membrane-embedded V region responsible for proton translocation. V-ATPase activity leads to acidification of endosomes, phagosomes, lysosomes, secretory vesicles, and the trans-Golgi network, with extracellular acidification occurring in some specialized cells.

View Article and Find Full Text PDF

Venetoclax is a specific B cell lymphoma 2 (BCL-2) inhibitor with promising activity against acute myeloid leukemia (AML), but its clinical efficacy as a single agent or in combination with hypomethylating agents (HMAs), such as azacitidine, is hampered by intrinsic and acquired resistance. Here, we performed a genome-wide CRISPR knockout screen and found that inactivation of genes involved in mitochondrial translation restored sensitivity to venetoclax in resistant AML cells. Pharmacologic inhibition of mitochondrial protein synthesis with antibiotics that target the ribosome, including tedizolid and doxycycline, effectively overcame venetoclax resistance.

View Article and Find Full Text PDF