In nutrient-starved bacteria, RelA and SpoT proteins have key roles in reducing cell growth and overcoming stresses. Here we identify functional SpoT orthologs in metazoa (named Mesh1, encoded by HDDC3 in human and Q9VAM9 in Drosophila melanogaster) and reveal their structures and functions. Like the bacterial enzyme, Mesh1 proteins contain an active site for ppGpp hydrolysis and a conserved His-Asp-box motif for Mn(2+) binding. Consistent with these structural data, Mesh1 efficiently catalyzes hydrolysis of guanosine 3',5'-diphosphate (ppGpp) both in vitro and in vivo. Mesh1 also suppresses SpoT-deficient lethality and RelA-induced delayed cell growth in bacteria. Notably, deletion of Mesh1 (Q9VAM9) in Drosophila induces retarded body growth and impaired starvation resistance. Microarray analyses reveal that the amino acid-starved Mesh1 null mutant has highly downregulated DNA and protein synthesis-related genes and upregulated stress-responsible genes. These data suggest that metazoan SpoT orthologs have an evolutionarily conserved function in starvation responses.

Download full-text PDF

Source
http://dx.doi.org/10.1038/nsmb.1906DOI Listing

Publication Analysis

Top Keywords

starvation responses
8
cell growth
8
spot orthologs
8
q9vam9 drosophila
8
mesh1
6
metazoan ortholog
4
spot
4
ortholog spot
4
spot hydrolyzes
4
hydrolyzes ppgpp
4

Similar Publications

Phosphorus is a key nutrient for all organisms. The study of phosphate metabolism and its regulation is important for understanding the evolutionary processes of regulatory systems in eukaryotic cells. The methylotrophic yeast is an efficient producer organism, and it is actively used in biotechnological production.

View Article and Find Full Text PDF

A pair of LysM receptors mediates symbiosis and immunity discrimination in Marchantia.

Cell

January 2025

New Cornerstone Science Laboratory, Key Laboratory of Plant Carbon Capture, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, SIBS, Chinese Academy of Sciences, Shanghai 200032, China; School of Life Sciences and Technology, Shanghai Tech University, Shanghai 201210, China. Electronic address:

Most land plants form symbioses with microbes to acquire nutrients but also must restrict infection by pathogens. Here, we show that a single pair of lysin-motif-containing receptor-like kinases, MpaLYR and MpaCERK1, mediates both immunity and symbiosis in the liverwort Marchantia paleacea. MpaLYR has a higher affinity for long-chain (CO7) versus short-chain chitin oligomers (CO4).

View Article and Find Full Text PDF

Polydatin-Induced Shift of Redox Balance and Its Anti-Cancer Impact on Human Osteosarcoma Cells.

Curr Issues Mol Biol

December 2024

Department of Clinical Sciences and Translational Medicine, University of Rome 'Tor Vergata', Via Montpellier 1, 00133 Rome, Italy.

Cancer cells demonstrate remarkable resilience by adapting to oxidative stress and undergoing metabolic reprogramming, making oxidative stress a critical target for cancer therapy. This study explores, for the first time, the redox-dependent anticancer effects of Polydatin (PD), a glucoside derivative of resveratrol, on the human Osteosarcoma (OS) cells SAOS-2 and U2OS. Using cell-based biochemical assays, we found that cytotoxic doses of PD (100-200 µM) promote ROS production, deplete glutathione (GSH), and elevate levels of both total iron and intracellular malondialdehyde (MDA), which are key markers of ferroptosis.

View Article and Find Full Text PDF

Single-cell decisions made in complex environments underlie many bacterial phenomena. Image-based transcriptomics approaches offer an avenue to study such behaviors, yet these approaches have been hindered by the massive density of bacterial messenger RNA. To overcome this challenge, we combined 1000-fold volumetric expansion with multiplexed error-robust fluorescence in situ hybridization (MERFISH) to create bacterial-MERFISH.

View Article and Find Full Text PDF

A Phosphate-Starvation Enhanced Purple Acid Phosphatase, GmPAP23 Mediates Intracellular Phosphorus Recycling and Yield in Soybean.

Plant Cell Environ

January 2025

Department of Plant Nutriton, Root Biology Center, State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Natural Resources and Environment, South China Agricultural University, Guangzhou, China.

Plant internal phosphorus (P) recycling is a complex process, which is vital for improving plant P use efficiency. However, the mechanisms underlying phosphate (Pi) release from internal organic-P form remains to be deciphered in crops. Here, we functionally characterised a Pi-starvation responsive purple acid phosphatase (PAP), GmPAP23 in soybean (Glycine max).

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!