The actin cytoskeleton and reactive oxygen species (ROS) both play crucial roles in various cellular processes. Previous research indicated a direct interaction between two key components of these systems: the WAVE1 subunit of the WAVE regulatory complex (WRC), which promotes actin polymerization and the p47phox subunit of the NADPH oxidase 2 complex (NOX2), which produces ROS. Here, using carefully characterized recombinant proteins, we find that activated p47phox uses its dual Src homology 3 domains to bind to multiple regions within the WAVE1 and Abi2 subunits of the WRC, without altering WRC\'s activity in promoting Arp2/3-mediated actin polymerization. Notably, contrary to previous findings, p47phox uses the same binding pocket to interact with both the WRC and the p22phox subunit of NOX2, albeit in a mutually exclusive manner. This observation suggests that when activated, p47phox may separately participate in two distinct processes: assembling into NOX2 to promote ROS production and engaging with WRC to regulate the actin cytoskeleton.

Wiskott-Aldrich syndrome protein family verprolin-homologous domain-containing protein 3 (WAVE3) is reported as an oncogene regulating cell proliferation and motility in multiple malignancies, while its role in tongue squamous cell carcinoma (TSCC) remains unknown. This study aimed to explore the expression and mechanism of WAVE3 in TSCC. We enrolled 64 TSCC patients admitted between June 2013 and February 2014 and collected their cancerous and adjacent normal tissues to determine WAVE3 expression by immunohistochemistry. The correlation of WAVE3 expression with TSCC patients\' pathological characteristics was analyzed. Then, a 7-year follow-up was conducted to observe the value of WAVE3 in evaluating patient outcomes. In addition, human TSCC SCC9, SCC25, and CAL27 cells were purchased and detected by Cell Counting Kit-8 (CCK-8), Transwell, and scratch-wound assays for their proliferation, invasion, and migration capacities, while real-time quantitative PCR (qRT-PCR) and Western blotting were utilized to quantify WAVE3 and epithelial-mesenchymal transition (EMT)-related protein expression, respectively. The most active cell lines were selected to be infected with lentiviral vectors that silenced WAVE3 (named WAVE3-sh group) and overexpressed WAVE3 cDNA (named WAVE3-OE group) to observe the impacts of interfering WAVE3 expression on TSCC cell biological behavior. The positive expression of WAVE3 in TSCC tissue was found to be obviously enhanced and predominantly located in the cytoplasm. In addition, close correlations were identified between WAVE3 and T staging, clinical staging, lymphatic metastasis, distant metastasis, and differentiation degree (P < 0.05). Increased WAVE3 expression predicted an elevated risk of death, as indicated by the follow-up analysis (P < 0.05). SCC9 was selected for subsequent experiments among various TSCC cell lines studied because it showed the most potent ability to proliferate, invade, and migrate (P < 0.05). Silencing WAVE3 expression in SCC9 cells decreased cell proliferation, invasion, migration, and EMT-related protein expression (P < 0.05), while increasing WAVE3 expression promoted SCC9 viability. WAVE3, which was highly expressed in TSCC, promoted EMT in tumor cells and accelerated their proliferation, invasion, and migration, which might provide a new theoretical basis for molecular targeted therapy of TSCC in the future.

Neurodevelopmental disorder with absent language and variable seizures (NEDALVS, # 618707) are characterized by delayed speech and motor development, ocular abnormalities, and seizures. NEDAVLS is an autosomal dominant disorder caused by de novo mutations in the wasp protein family member 1 (WASF1) gene.
We identified a de novo nonsense variant c.1516 C > T (p.Arg506*) of WASF1 gene (NM_003931.3) in two pediatric female patients with delayed motor and language development.
This case demonstrates the effective role of WES in the diagnosis of NEDALVS. To the best of our knowledge, this variant has not been reported in the Chinese population. This contributes to our further understanding of the disease and to research related to the genetic and clinical heterogeneity, the treatment and prognosis of the disease.

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is characterized by various disabling symptoms including exercise intolerance and is diagnosed in the absence of a specific cause, making its clinical management challenging. A better understanding of the molecular mechanism underlying this apparent bioenergetic deficiency state may reveal insights for developing targeted treatment strategies. We report that overexpression of Wiskott-Aldrich Syndrome Protein Family Member 3 (WASF3), here identified in a 38-y-old woman suffering from long-standing fatigue and exercise intolerance, can disrupt mitochondrial respiratory supercomplex formation and is associated with endoplasmic reticulum (ER) stress. Increased expression of WASF3 in transgenic mice markedly decreased their treadmill running capacity with concomitantly impaired respiratory supercomplex assembly and reduced complex IV levels in skeletal muscle mitochondria. WASF3 induction by ER stress using endotoxin, well known to be associated with fatigue in humans, also decreased skeletal muscle complex IV levels in mice, while decreasing WASF3 levels by pharmacologic inhibition of ER stress improved mitochondrial function in the cells of the patient with chronic fatigue. Expanding on our findings, skeletal muscle biopsy samples obtained from a cohort of patients with ME/CFS showed increased WASF3 protein levels and aberrant ER stress activation. In addition to revealing a potential mechanism for the bioenergetic deficiency in ME/CFS, our study may also provide insights into other disorders associated with fatigue such as rheumatic diseases and long COVID.

Lung adenocarcinoma (LUAD) is the predominant type of non-small lung cancer (NSCLC) with strong invasive ability and poor prognosis. The drug resistance related genes are potentially associated with prognosis of LUAD. Our research aimed to identify the drug resistance related genes and explore their potential prognostic value in LUAD patients. The data used in this study were obtained from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. Firstly, we screened drug resistance related genes in LUAD by differential gene analysis, univariate Cox regression and drug sensitivity analyses. Subsequently, we constructed a risk score model using LASSO Cox regression analysis, and verified whether the risk score can predict the survival of LUAD patients independent of other factors. Moreover, we explored the immune infiltration of 22 immune cells between high-risk and low-risk patients. Totally 10 drug-resistance positively related genes (PLEK2, TFAP2A, KIF20A, S100P, GDF15, HSPB8, SASH1, WASF3, LAMA3 and TCN1) were identified in LUAD. The risk score model of LUAD constructed with these 10 genes could reliably predict the prognosis of LUAD patients. 18 pathways were significantly activated in high-risk group compared with low-risk group. In addition, the infiltration proportion of multiple immune cells was significantly different between high-risk and low-risk groups, and the proportion of M1 phagocytes was significantly higher in the high-risk group compared with the low-risk group. The drug resistance related genes (PLEK2, TFAP2A, KIF20A, S100P, GDF15, HSPB8, SASH1, WASF3, LAMA3 and TCN1) could predict the prognosis of LUAD patients. Clarifying the roles and mechanisms of these 10 genes in regulating drug resistance in LUAD will help to improve individualized clinical treatment protocols and predict patient sensitivity to treatment.

The WAVE regulatory complex (WRC), composed of five components-Cyfip1/Sra1, WAVE/Scar, Abi, Nap1/Nckap1, and Brk1/HSPC300-is essential for proper actin cytoskeletal dynamics and remodeling in eukaryotic cells, likely by matching various patterned signals to Arp2/3-mediated actin nucleation. Accumulating evidence from recent studies has revealed diverse functions of the WRC in neurons, demonstrating its crucial role in dictating the assembly of molecular complexes for the patterning of various trans-synaptic signals. In this review, we discuss recent exciting findings on the physiological role of the WRC in regulating synaptic properties and highlight the involvement of WRC dysfunction in various brain disorders.

The tumor microenvironment (TME) is constituted by a great diversity of highly dynamic cell populations, each of which contributes ligands, receptors, soluble proteins, mRNAs, and miRNAs, in order to regulate cellular activities within the TME and even promote processes such as angiogenesis or metastasis. Intravasated platelets (PLT) undergo changes in the TME that convert them into tumor-educated platelets (TEP), which supports the development of cancer, angiogenesis, and metastasis through the degranulation and release of biomolecules. Several authors have reported that the deregulation of PF4, VEGF, PDGF, ANG-1, WASF3, LAPTM4B, TPM3, and TAC1 genes participates in breast cancer progression, angiogenesis, and metastasis. The present work aimed to analyze the expression levels of this set of genes in tumor tissues and platelets derived from breast cancer patients by reverse transcription-quantitative polymerase chain reaction (RTqPCR) assays, in order to determine if there was an expression correlation between these sources and to take advantage of the new information to be used in possible diagnosis by liquid biopsy. Data from these assays showed that platelets and breast cancer tumors present similar expression levels of a subset of these genes\' mRNAs, depending on the molecular subtype, comorbidities, and metastasis presence.

The actin 2/3 complex (Arp2/3) regulates actin polymerization and nucleation of actin filaments, is associated with cell motility, and has been shown to play a key role in the invasion and migration of cancer cells. nucleation-promoting factor (NPF) such as N-WASP (neural-WASP famly verprolin-homologous protein family), WAVE (WASP famly verprolin-homologous protein family), and WASH (WASP and Scar homologue) undergo conformational changes upon receipt of multiple upstream signals including Rho family GTPases, cdc42 (Cell division control protein 42 homolog), and phosphatidylinositol 4,5-bisphosphate (PtdIns 4,5 P2) to bind and activate the Arp2/3 complex. Once activated, the Arp2/3 complex forms actin-based membrane protrusions necessary for cancer cells to acquire an invasive phenotype. Therefore, how to influence the invasion and migration of cancer cells by regulating the activity of the Arp2/3 complex has attracted great research interest in recent years. Several studies have explored the effects of phosphorylation modifications of cortactin and several NPFs (Nucleation Promoting Factor) including N-WASP and WAVE on the activity of the Arp2/3 complex and ultimately on cancer cell invasiveness, and have attempted to suggest new strategies for antiinvasive therapy as a result. Other studies have highlighted the potential of targeting genes encoding partial or complete proteins of the Arp2/3 complex as a therapeutic strategy to prevent cancer cell invasion and metastasis. This article reviews the role of the Arp2/3 complex in the development, invasion, and metastasis of different types of cancer and the mechanisms regulating the activity of the Arp2/3 complex.

Rho family GTPases regulate both linear and branched actin dynamics by activating downstream effectors to facilitate the assembly and function of complex cellular structures such as lamellipodia and contractile actomyosin rings. Wiskott-Aldrich Syndrome (WAS) family proteins are downstream effectors of Rho family GTPases that usually function in a one-to-one correspondence to regulate branched actin nucleation. In particular, the WAS protein Scar/WAVE has been shown to exhibit one-to-one correspondence with Rac GTPase. Here we show that Rac and SCAR are recruited to cell wounds in the Drosophila repair model and are required for the proper formation and maintenance of the dynamic actomyosin ring formed at the wound periphery. Interestingly, we find that SCAR is recruited to wounds earlier than Rac and is still recruited to the wound periphery in the presence of a potent Rac inhibitor. We also show that while Rac is important for actin recruitment to the actomyosin ring, SCAR serves to organize the actomyosin ring and facilitate its anchoring to the overlying plasma membrane. These differing spatiotemporal recruitment patterns and wound repair phenotypes highlight the Rac-independent functions of SCAR and provide an exciting new context in which to investigate these newly uncovered SCAR functions.

The actin cytoskeleton impacts practically every function of a eukaryotic cell. Historically, the best-characterized cytoskeletal activities are in cell morphogenesis, motility, and division. The structural and dynamic properties of the actin cytoskeleton are also crucial for establishing, maintaining, and changing the organization of membrane-bound organelles and other intracellular structures. Such activities are important in nearly all animal cells and tissues, although distinct anatomical regions and physiological systems rely on different regulatory factors. Recent work indicates that the Arp2/3 complex, a broadly expressed actin nucleator, drives actin assembly during several intracellular stress response pathways. These newly described Arp2/3-mediated cytoskeletal rearrangements are coordinated by members of the Wiskott-Aldrich Syndrome Protein (WASP) family of actin nucleation-promoting factors. Thus, the Arp2/3 complex and WASP-family proteins are emerging as crucial players in cytoplasmic and nuclear activities including autophagy, apoptosis, chromatin dynamics, and DNA repair. Characterizations of the functions of the actin assembly machinery in such stress response mechanisms are advancing our understanding of both normal and pathogenic processes, and hold great promise for providing insights into organismal development and interventions for disease.