Monocyte-to-macrophage differentiation and subsequent foam cell formation are key processes that contribute to plaque build-up during the progression of atherosclerotic lesions. Palmitoylation enzymes are known to play pivotal roles in the development and progression of inflammatory diseases. However, their specific impact on atherosclerosis development remains unclear.
View Article and Find Full Text PDFThe significance of protein S-palmitoylation in angiogenesis has been largely overlooked, leaving various aspects unexplored. Recent identification of Gpx1 as a palmitoylated protein has generated interest in exploring its potential involvement in novel pathological mechanisms related to angiogenesis. In this study, we demonstrate that Gpx1 undergoes palmitoylation at cysteine-76 and -113, with PPT1 playing a crucial role in modulating the depalmitoylation of Gpx1.
View Article and Find Full Text PDFSignal Transduct Target Ther
September 2024
The downregulation of Cadm4 (Cell adhesion molecular 4) is a prominent feature in demyelination diseases, yet, the underlying molecular mechanism remains elusive. Here, we reveal that Cadm4 undergoes specific palmitoylation at cysteine-347 (C347), which is crucial for its stable localization on the plasma membrane (PM). Mutation of C347 to alanine (C347A), blocking palmitoylation, causes Cadm4 internalization from the PM and subsequent degradation.
View Article and Find Full Text PDFRap2b, a proto-oncogene upregulated in colorectal cancer (CRC), undergoes protein S-palmitoylation at specific C-terminus sites (C176/C177). These palmitoylation sites are crucial for Rap2b localization on the plasma membrane (PM), as mutation of C176 or C177 results in cytosolic relocation of Rap2b. Our study demonstrates that Rap2b influences cell migration and invasion in CRC cells, independent of proliferation, and this activity relies on its palmitoylation.
View Article and Find Full Text PDFSept8 is a vesicle associated protein and there are two typical transcriptional variants (Sept8-204 and Sept8-201) expressed in mice brain. Interestingly, the coexpression of Sept8-204/Sept5 induces the formation of small sized vesicle-like structure, while that of the Sept8-201/Sept5 produces large puncta. Sept8 is previously shown to be palmitoylated.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
December 2023
Massive GGGGCC (G4C2) repeat expansion in and the resulting loss of C9orf72 function are the key features of ~50% of inherited amyotrophic lateral sclerosis and frontotemporal dementia cases. However, the biological function of C9orf72 remains unclear. We previously found that C9orf72 can form a stable GTPase activating protein (GAP) complex with SMCR8 (Smith-Magenis chromosome region 8).
View Article and Find Full Text PDFSeptin proteins are involved in diverse physiological functions, including the formation of specialized cytoskeletal structures. Septin 8 (Sept8) is implicated in spine morphogenesis and dendritic branching through palmitoylation. We explored the role and regulation of a Sept8 variant in human neural-like cells and in the mouse brain.
View Article and Find Full Text PDFp62 is a well-characterized autophagy receptor that recognizes and sequesters specific cargoes into autophagosomes for degradation. p62 promotes the assembly and removal of ubiquitinated proteins by forming p62-liquid droplets. However, it remains unclear how autophagosomes efficiently sequester p62 droplets.
View Article and Find Full Text PDFProtein palmitoylation is tightly related to tumorigenesis or tumor progression as many oncogenes or tumor suppressors are palmitoylated. AEG-1, an oncogene, is commonly elevated in a variety of human malignancies, including hepatocellular carcinoma (HCC). Although AEG-1 was suggested to be potentially modified by protein palmitoylation, the regulatory roles of AEG-1 palmitoylation in tumor progression of HCC has not been explored.
View Article and Find Full Text PDFThe dynamics of synaptic vesicles (SVs) within presynaptic domains are tightly controlled by synapsin1 phosphorylation; however, the mechanism underlying the anchoring of synapsin1 with F-actin or SVs is not yet fully understood. Here, we found that Syn1 is modified with protein palmitoylation, and examining the roles of Syn1 palmitoylation in neurons led us to uncover that Syn1 palmitoylation is negatively regulated by its phosphorylation; together, they manipulate the clustering and redistribution of SVs. Using the combined approaches of electron microscopy and genetics, we revealed that Syn1 palmitoylation is vital for its binding with F-actin but not SVs.
View Article and Find Full Text PDFProtein S-palmitoylation (hereinafter referred to as protein palmitoylation) is a reversible lipid posttranslational modification catalyzed by the zinc finger DHHC-type containing (ZDHHC) protein family. The reverse reaction, depalmitoylation, is catalyzed by palmitoyl-protein thioesterases (PPTs), including acyl-protein thioesterases (APT1/2), palmitoyl protein thioesterases (PPT1/2), or alpha/beta hydrolase domain-containing protein 17A/B/C (ABHD17A/B/C). Proteins encoded by several oncogenes and tumor suppressors are modified by palmitoylation, which enhances the hydrophobicity of specific protein subdomains, and can confer changes in protein stability, membrane localization, protein-protein interaction, and signal transduction.
View Article and Find Full Text PDFSchistosomiasis is caused by parasitic flatworms known as schistosomes and affects over 200 million people worldwide. Prevention of T cell exhaustion by blockade of PD-1 results in clinical benefits to cancer patients and clearance of viral infections, however it remains largely unknown whether loss of PD-1 could prevent or cure schistosomiasis in susceptible mice. In this study, we found that S.
View Article and Find Full Text PDFBackground: Synaptic abnormalities in synaptic proteins are the initial hallmarks of Alzheimer's disease (AD). The higher level of palmitoylation of synaptic proteins was closely associated with amyloid-β (Aβ) in AD. Cattle encephalon glycoside and ignotin (CEGI) have been shown to act as multitarget neurotrophic agents in APPswe/PS1dE9 (APP/PS1) transgenic AD mice.
View Article and Find Full Text PDFThe reversible lipid modification, S-palmitoylation, plays regulatory roles in various physiological processes, e.g., neuronal plasticity and organs development; however, the roles of palmitoylation engaged in testis have yet remained unexplored.
View Article and Find Full Text PDFPalmitoylation is a special kind of lipid modification that targets proteins to membranes. This protocol introduces the acyl-biotin exchange (ABE) assay to determine the palmitoylation of protein cysteines in yeast. Palmitoylation is exchanged by biotinylated compounds so that the palmitoyl proteins can be affinity-purified for downstream assay by western blot.
View Article and Find Full Text PDFMacroautophagy/autophagy is special because the double-layer lipid-formed autophagosome is formed by generation. Phosphatidylinositol-3-phosphate (PtdIns3P) produced by class III phosphatidylinositol 3-kinase complex I (PtdIns3K-CI) is an essential source lipid for the formation of autophagosomes. However, how autophagy is initiated is unknown.
View Article and Find Full Text PDFHow autophagy initiation is regulated and what the functional significance of this regulation is are unknown. Here, we characterized the role of yeast Vac8 in autophagy initiation through recruitment of PIK3C3-C1 to the phagophore assembly site (PAS). This recruitment is dependent on the palmitoylation of Vac8 and on its middle ARM domains for binding PIK3C3-C1.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
March 2021
The homeostasis of protein palmitoylation and depalmitoylation is essential for proper physiological functions in various tissues, in particular the central nervous system (CNS). The dysfunction of PPT1 (PPT1-KI, infantile neuronal ceroid lipofuscinosis [INCL] mouse model), which catalyze the depalmitoylation process, results in serious neurodegeneration accompanied by severe astrogliosis in the brain. Endeavoring to determine critical factors that might account for the pathogenesis in CNS by palm-proteomics, glial fibrillary acidic protein (GFAP) was spotted, indicating that GFAP is probably palmitoylated.
View Article and Find Full Text PDFZdhhc family genes are composed of 24 members that regulate palmitoylation, a post-translational modification process for proteins. Mutations in genes that alter palmitoylation or de-palmitoylation could result in neurodegenerative diseases and inflammatory disorders. In this study, we found that Zdhhc2 was robustly induced in psoriatic skin and loss of Zdhhc2 in mice by CRISPR/Cas9 dramatically inhibited pathology of the ear skin following imiquimod treatment.
View Article and Find Full Text PDFNeutrophils are crucial for immunity and play important roles in inflammatory diseases; however, mouse models selectively deficient in neutrophils are limited, and neutrophil-specific diphtheria toxin (DT)-based depletion system has not yet been established. In this study, we generated a novel knock-in mouse model expressing diphtheria toxin receptor (DTR) under control of the endogenous Ly6G promoter. We showed that DTR expression was restricted to Ly6G neutrophils and complete depletion of neutrophils could be achieved by DT treatment at 24-48 h intervals.
View Article and Find Full Text PDFBackground: Astroglioma, one major form of brain tumors, has remained principally tough to handle for decades, due to the complexity of tumor pathology and the poor response to chemo- and radio-therapies.
Methods: Our previous study demonstrated that nifurtimox could regulate the signaling axis of AKT-GSK3β in various tumor types including the astroglioma U251 cells. Intriguingly, earlier case studies suggested that nifurtimox could possibly permeate the blood brain barrier and arrest neuroblastoma in the brain.
Neuroblastoma was one of the most life-threatening cancer developed in children, yet the conventional therapies currently used leave an unmet gap for clinical requirements. Temozolomide is the first line of drug in the treatment of neuroblastorma nowadays. Giving the fact that temozolomide treatment offered limited healing effect and patients responded divergently, an alternative beneficial path is urgently requested.
View Article and Find Full Text PDFBackground: Angiogenesis is tightly linked to inflammation. Cytokines of interleukin 1 (IL-1) family are key mediators in modulating inflammatory responses.
Methods: In this study, we examined the role of IL-38, a member of the IL-1 family, in mediating inflammation-induced angiogenesis.