Adenosine monophosphate-activated protein kinase (AMPK) is a conserved sensor of intracellular energy activated in response to low nutrient availability and environmental stress. In a screen for conserved substrates of AMPK, we identified ULK1 and ULK2, mammalian orthologs of the yeast protein kinase Atg1, which is required for autophagy. Genetic analysis of AMPK or ULK1 in mammalian liver and Caenorhabditis elegans revealed a requirement for these kinases in autophagy. In mammals, loss of AMPK or ULK1 resulted in aberrant accumulation of the autophagy adaptor p62 and defective mitophagy. Reconstitution of ULK1-deficient cells with a mutant ULK1 that cannot be phosphorylated by AMPK revealed that such phosphorylation is required for mitochondrial homeostasis and cell survival during starvation. These findings uncover a conserved biochemical mechanism coupling nutrient status with autophagy and cell survival.
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http://dx.doi.org/10.1126/science.1196371 | DOI Listing |
Cell Div
December 2024
Institute for Research in Immunology and Cancer, Département de biochimie et médecine moléculaire, Université de Montréal, Montreal, Québec, Canada.
Background: Mitosis and cytokinesis are regulated by reversible phosphorylation events controlled by kinases and phosphatases. Drosophila Polo kinase, like its human ortholog PLK1, plays several roles in this process. Multiple mechanisms contribute to regulate Polo/PLK1 activity, localization and interactions.
View Article and Find Full Text PDFJ Dermatol Sci
November 2024
Department of Dermatology, Plastic Surgery Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China. Electronic address:
Background: Mutations in gamma-secretase complex (GSC) genes are associated with hidradenitis suppurativa (HS), and toll-like receptor (TLR) 2 is elevated in HS lesions. However, it remains unclear whether TLR2 is upregulated in the skin lesions of patients with HS with GSC gene variants, and the role of its upregulation in the pathogenesis of this disease are unknown.
Objective: To investigate the role of TLR2 upregulation in NCSTN and PSENEN knockdown keratinocytes.
J Shoulder Elbow Surg
December 2024
Department of Orthopaedic Surgery, Konkuk University Medical Center, Seoul, Korea.
Background: Muscle atrophy after the rupture of a rotator cuff (RC) tendon is a major factor that increases the risk of secondary complications and re-rupture. Metformin, a type 2 diabetes treatment, can be used to modulate intracellular signaling pathways that promote muscle growth. This study aimed to verify whether systemic metformin administration could prevent supraspinatus (SS) atrophy after RC rupture in a rat model.
View Article and Find Full Text PDFJ Plant Physiol
December 2024
Federal Scientific Centre of the East Asia Terrestrial Biodiversity of the Far East Branch of the Russian Academy of Sciences, Vladivostok, 690022, Russia.
Calcium-dependent protein kinases (CDPKs) are very effective calcium signal decoders due to their unique structure, which mediates substrate-specific [Ca] signalling through phosphorylation. However, Ca-dependence makes it challenging to study CDPKs. This work focused on the effects of the overexpression of native and modified forms of the AtCPK1 gene on the tolerance of tobacco plants to heat and cold.
View Article and Find Full Text PDFJ Photochem Photobiol B
December 2024
Fisheries Research Institute of Fujian, National Research and Development Center for Marine Fish Processing, Key Laboratory of Cultivation and High-value Utilization of Marine Organisms in Fujian Province, Xiamen, China. Electronic address:
Takifugu bimaculatus, a pufferfish species farmed in Fujian Province, is known for its non-toxic flesh and collagen-rich skin. We identified a novel collagen-derived matrix metalloproteinase 1 (MMP-1) inhibitory peptide, from T. bimaculatus skin with potent anti-photoaging properties.
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