SH3

Daidzein is a major isoflavone compound with an immense pharmaceutical value. This study applied a novel P450 CYP82D26 which can biosynthesize daidzein from (2 S )-naringenin. However, the recombinant P450 systems often suffer from low coupling efficiency, leading to an electron transfer efficiency decrease and harmful reactive oxygen species release, thereby compromising their stability and catalytic efficiency. To address these challenges, the SH3-GBD-PDZ (SGP) protein scaffold was applied to assemble a multienzyme system comprising CYP82D26, P450 reductase, and NADP+ -dependent aldehyde reductase in desired stoichiometric ratios...

Biomolecular condensates play a major role in cell compartmentalization, besides membrane-enclosed organelles. The multivalent SLP65 and CIN85 proteins are proximal B-cell antigen receptor (BCR) signal effectors and critical for proper immune responses. In association with intracellular vesicles, the two effector proteins form phase separated condensates prior to antigen stimulation, thereby preparing B lymphocytes for rapid and effective activation upon BCR ligation. Within this tripartite system, 6 proline-rich motifs (PRMs) of SLP65 interact promiscuously with 3 SH3 domains of the CIN85 monomer, establishing 18 individual SH3-PRM interactions whose individual dissociation constants we determined...

BACKGROUND: FLI1 is an oncogenic transcription factor that promotes diverse malignancies through mechanisms that are not fully understood. Herein, FLI1 is shown to regulate the expression of Ubiquitin Associated and SH3 Domain Containing A/B (UBASH3A/B) genes. UBASH3B and UBASH3A are found to act as an oncogene and tumor suppressor, respectively, and their combined effect determines erythroleukemia progression downstream of FLI1. METHODS: Promoter analysis combined with luciferase assays and chromatin immunoprecipitation (ChIP) analysis were applied on the UBASH3A/B promoters...

The adaptor protein Grb2, or Growth factor receptor bound protein 2, possesses a pivotal role in the transmission of fundamental molecular signals in the cell. Despite lacking enzymatic activity, Grb2 functions as a dynamic assembly platform, orchestrating intracellular signals through its modular structure. This study delves into the energetic communication of Grb2 domains, focusing on the folding and binding properties of the C-SH3 domain linked to its neighboring SH2 domain. Surprisingly, while the folding and stability of C-SH3 remain robust and unaffected by SH2 presence, significant differences emerge in the binding properties when considered within the tandem context compared to isolated C-SH3...

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 SH3 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...

Inhibition of Reactive Oxygen Species (ROS) is one of the strategies that Mycobacterium tuberculosis (Mtb) employs as its defence mechanism. In this study, the role of PPE15 (Rv1039c), a late-stage protein, has been investigated in modulating the cellular ROS. We discovered PPE15 to be a secretory protein that downregulates ROS generation in THP1 macrophages. Our in-silico analysis revealed the presence of a eukaryote-like SH3 (SH3e) domain in PPE15. The predicted SH3e-domain of PPE15 was found to interact with cytosolic components of NADPH Oxidase (NOX), p67phox and p47phox through molecular docking...

Various chimeric lysins have been developed as efficacious antibiotics against multidrug-resistant bacteria, but direct comparisons of their antibacterial activities have been difficult due to the preparation of multiple recombinant chimeric lysins. Previously, we reported an Escherichia coli cell-free expression method to better screen chimeric lysins against Staphylococcus aureus , but we still needed to increase the amounts of expressed proteins enough to be able to detect them non-isotopically for quantity comparisons...

Acute lymphoblastic leukemia (ALL) with fusions of ABL-class tyrosine kinase genes other than BCR::ABL1 occurs in approximately 3% of children with ALL. The tyrosine kinase genes involved in this BCR::ABL1-like (Ph-like) subtype include ABL1, PDGFRB, ABL2, and CSF1R, which each have up to ten described partner genes. ABL-class ALL resembles BCR::ABL1-positive ALL by a similar gene expression profile, a poor response to chemotherapy, and sensitivity to tyrosine kinase inhibitors (TKIs). There is a lack of comprehensive data regarding TKI sensitivity for the heterogeneous group of ABL-class ALL...

Adaptor proteins play a pivotal role in cellular signaling mediating a multitude of protein-protein interaction critical for cellular homeostasis. Dysregulation of these interactions has been linked to the onset of various cancer pathologies and exploited by viral pathogens during host cell takeover. CrkL is an adaptor protein composed of an N-terminal SH2 domain followed by two SH3 domains that mediate interactions with diverse partners through the recognition of specific binding motifs. In this study, we employed proteomic peptide-phage display (ProP-PD) to comprehensively explore the short linear motif (SLiM)-based interactions of CrkL...

BACKGROUND: Vascular BK channel, composed of the large conductance Ca2+ -activated K+ channel αsubunit and the large conductance Ca2+ -activated K+ channel β1 subunits, is a key determinant of coronary vasorelaxation and its function is impaired in diabetic vessels. However, our knowledge of diabetic BK channel dysregulation is incomplete. The Sorbin homology and Sorbs2 (SH3 [Src homology 3] domain-containing protein 2) are ubiquitously expressed in arteries, but its role in vascular pathophysiology is unknown...

UBASH3A and UBASH3B are protein families of atypical protein tyrosine phosphatases that function as regulators of various cellular processes during mammalian development. As UBASH3A has only mild phosphatase activity, its regulatory effects are based on the phosphatase-independent mechanisms. On the contrary, UBASH3B has strong phosphatase activity, and the suppression of its receptor signalling is mediated by Syk and Zap-70 kinases. The regulatory functions of UBASH3A and UBASH3B are particularly evident in the lymphoid tissues and kidney development...

ASPP2 and iASPP bind to p53 through their conserved ANK-SH3 domains to respectively promote and inhibit p53-dependent cell apoptosis. While crystallography has indicated that these two proteins employ distinct surfaces of their ANK-SH3 domains to bind to p53, solution NMR data has suggested similar surfaces. In this study, we employed multi-scale molecular dynamics (MD) simulations combined with free energy calculations to reconcile the discrepancy in the binding modes. We demonstrated that the binding mode based solely on a single crystal structure does not enable iASPP's RT loop to engage with p53's C-terminal linker-a verified interaction...

Filopodia are narrow actin-rich protrusions with important roles in neuronal development where membrane-binding adaptor proteins have emerged as upstream regulators that link membrane interactions to actin regulators, for example I-BAR and F-BAR domain-containing proteins interacting with Ena/VASP and formins. To explore the significance of the F-BAR neuronal membrane adaptor TOCA-1 in filopodia we used quantitative analysis of TOCA-1 and filopodial dynamics in Xenopus retinal ganglion cells, where Ena/VASP proteins have a native role in filopodial extension...

Nox4-derived H2 O2 generation plays an important role in the pathogenesis of chronic kidney diseases (CKDs) such as diabetic nephropathy (DN). Here, we showed that SH3 domain-containing Ysc84-like 1 (SH3YL1), a Nox4 cytosolic activator, regulated DN. Streptozotocin (STZ)-induced type Ⅰ diabetic models in SH3YL1 whole-body knockout (KO) mice and podocyte-specific SH3YL1 conditional KO (Nphs2-Cre/SH3YL1fl/fl ) mice were established to investigate the function of SH3YL1 in DN. The expression of fibrosis markers and inflammatory cytokines, the generation of oxidative stress, and the loss of podocytes were suppressed in diabetic SH3YL1 KO and Nphs2-Cre/SH3YL1fl/fl mice, compared to diabetic control mice...

Human papillomaviruses (HPV) are a major cause of malignancy, contributing to ∼5% of all human cancers worldwide, including most cervical cancer cases and a growing number of ano-genital and oral cancers. The major HPV viral oncogenes, E6 and E7, manipulate many host cellular pathways that promote cell proliferation and survival, predisposing infected cells to malignant transformation. Despite the availability of highly effective vaccines, there are still no specific anti-viral therapies targeting HPV or treatments for HPV-associated cancers...

SRC homology 3 (SH3) domains are critical interaction modules that orchestrate the assembly of protein complexes involved in diverse biological processes. They facilitate transient protein-protein interactions by selectively interacting with proline-rich motifs (PRMs). A database search revealed 298 SH3 domains in 221 human proteins. Multiple sequence alignment of human SH3 domains is useful for phylogenetic analysis and determination of their selectivity towards PRM-containing peptides (PRPs). However, a more precise functional classification of SH3 domains is achieved by constructing a phylogenetic tree only from PRM-binding residues and using existing SH3 domain-PRP structures and biochemical data to determine the specificity within each of the 10 families for particular PRPs...

BACKGROUND AND AIMS: TGFβ1 induces hepatic stellate cell (HSC) activation into metastasis-promoting cancer-associated fibroblasts (CAFs), but how the process is fueled remains incompletely understood. We studied metabolic reprograming induced by TGFβ1 in HSCs. APPROACHES AND RESULTS: Activation of cultured primary human HSCs was assessed by expression of myofibroblast markers. Glucose transporter 1 (Glut1) of murine HSC was disrupted by Cre /LoxP recombination...

Protein tyrosine kinase 6 (PTK6), also known as breast tumor kinase (BRK), serves as a non-receptor intracellular tyrosine kinase within the Src kinases family. Structurally resembling other Src kinases, PTK6 possesses an Src homology 3 (SH3) domain, an Src homology 2 (SH2) domain, and a tyrosine kinase domain (SH1). While considerable efforts have been dedicated to designing PTK6 inhibitors targeting the SH1 domain, which is responsible for kinase activity in various pathways, it has been observed that solely inhibiting the SH1 domain does not effectively suppress PTK6 activity...

Oleosins (OLEs) are a class of small but abundant structural proteins that play essential roles in the formation and stabilization of lipid droplets (LDs) in seeds of oil crops. Despite the proposal of five oleosin clades (i.e., U, SL, SH, T, and M) in angiosperms, their evolution in eudicots has not been well-established. In this study, we employed Brassicales, an economically important order of flowering plants possessing the lineage-specific T clade, as an example to address this issue. Three to 10 members were identified from 10 species representing eight plant families, which include Caricaceae, Moringaceae, Akaniaceae, Capparaceae, and Cleomaceae...

Alzheimer's disease (AD) is the leading cause of dementia and lacks highly effective treatments. Tau-based therapies hold promise. Tau reduction prevents amyloid-β-induced dysfunction in preclinical models of AD and also prevents amyloid-β-independent dysfunction in diverse disease models, especially those with network hyperexcitability, suggesting that strategies exploiting the mechanisms underlying Tau reduction may extend beyond AD. Tau binds several SH3 domain-containing proteins implicated in AD via its central proline-rich domain...