DUSP10 Human

What is the molecular structure and basic function of DUSP10?

DUSP10 is a member of the protein-tyrosine phosphatase family that contains two Cdc25 homology regions, a C-terminal catalytic domain, and a unique 150 N-terminal amino acid sequence that distinguishes it from other family members. As a dual-specificity phosphatase, DUSP10 inactivates target kinases by dephosphorylating both phosphoserine/threonine and phosphotyrosine residues, primarily targeting members of the MAPK superfamily involved in cellular proliferation and differentiation . The human DUSP10 recombinant protein contains 359 amino acids (residues 149-482) with a molecular mass of approximately 40.4 kDa .

How is DUSP10 expressed in human tissues?

DUSP10 has two primary transcripts of approximately 3.4 kb and 2.4 kb identified within the human genome. The longer transcript is widely expressed in human tissues, particularly in skeletal muscle and liver, and its expression increases in response to stress stimuli. In contrast, tissue-specific expression patterns appear in mice, where a 3.5 kb transcript is widely expressed, but a 2.7 kb mRNA splice variant is specifically expressed in mouse and rat testis .

How is DUSP10 gene expression regulated?

DUSP10 regulation involves multiple mechanisms. Interestingly, DUSP10 expression can be induced by MAPKs themselves, suggesting a negative feedback regulatory loop. Additionally, cytotoxic agents like Shigella toxin (Stx1 or Verotoxin) and lipopolysaccharide (LPS) can induce DUSP10 expression . On the post-transcriptional level, DUSP10 is negatively regulated by several microRNAs, including miR-21, miR-30b, miR-155, miR-181, and miR-92a, which have specific binding sites in its 3'-untranslated region .

Which specific MAPK pathways does DUSP10 regulate, and with what selectivity?

DUSP10 primarily targets and inactivates p38 MAPK and JNK/SAPK (c-Jun N-terminal kinase/stress-activated protein kinase) pathways, with relatively minimal effects on ERK pathways. This selectivity profile (p38 ≈ JNK/SAPK >> ERK) makes DUSP10 particularly important in stress and inflammatory responses . Through direct interaction with MAPK14 (p38α) and MAPK8 (JNK1), DUSP10 dephosphorylates these kinases, downregulating their signaling cascades and ultimately affecting transcription factor activation, particularly AP-1 .

How does DUSP10 affect T cell signaling in immune responses?

DUSP10 acts as a key negative regulator of IL-33-induced cytokine production in Th2 cells. In ST2hi pathogenic Th2 cells, DUSP10 expression inhibits IL-33-induced cytokine production through dephosphorylation and inactivation of p38 MAPK, leading to reduced GATA3 activity . This mechanism helps explain why ST2hi pathogenic Th2 cells produce IL-5 upon T cell receptor stimulation but not in response to IL-33 treatment, unlike ILC2 cells which do respond to IL-33 stimulation .

What are the consequences of DUSP10 deficiency on immune signaling?

Studies in DUSP10-deficient mice demonstrate enhanced vascular inflammatory responses, increased p38 activation, greater neutrophil accumulation, and heightened production of pro-inflammatory cytokines like IL-6, TNF-α, and MIP-2 in response to inflammatory stimuli . Notably, DUSP10 deficiency renders ST2hi Th2 cells capable of producing IL-5 upon IL-33 stimulation . Additionally, DUSP10-deficient mice show resistance to experimental autoimmune encephalitis (EAE), with enhanced antigen presentation by dendritic cells and increased IFN-γ production by T cells .

What recombinant protein options are available for studying DUSP10 function?

Researchers can utilize human recombinant DUSP10 protein produced in E. coli expression systems. These typically contain the catalytically active portion of DUSP10 (amino acids 149-482) with an N-terminal His-tag for purification purposes. Commercial preparations (such as those from ProspecBio, catalog #ENZ-238) are generally supplied as sterile-filtered colorless solutions containing buffer components (20mM Tris-HCl buffer pH 8.0, 200mM NaCl, 2mM DTT) and 50% glycerol for stability . For long-term storage, it's recommended to store the protein at -20°C with the addition of carrier proteins (0.1% HSA or BSA) and to avoid multiple freeze-thaw cycles .

What genetic approaches have proven effective in DUSP10 functional studies?

Genetic knockout models, particularly DUSP10-deficient mice, have been instrumental in elucidating DUSP10's role in immune regulation. These models have revealed DUSP10's function in limiting inflammatory responses, T-cell activation, and disease progression in models like EAE and sepsis-induced lung injury . For cellular studies, siRNA and shRNA approaches targeting DUSP10 have been employed to examine its role in cancer cell proliferation, as demonstrated in lower-grade glioma studies . CRISPR-Cas9 genome editing offers additional precise options for manipulating DUSP10 expression in various experimental systems.

What phosphatase activity assays are recommended for DUSP10 functional analysis?

For measuring DUSP10 phosphatase activity, researchers typically employ in vitro phosphatase assays using synthetic phosphopeptide substrates or pre-phosphorylated recombinant MAPKs (particularly p38 and JNK). The detection of phosphate release can be quantified using malachite green-based colorimetric assays or fluorescent substrate-based approaches. When studying DUSP10 in cellular contexts, monitoring the phosphorylation status of its primary substrates (phospho-p38 and phospho-JNK) via western blotting or phospho-specific flow cytometry provides indirect but physiologically relevant measures of DUSP10 activity.

How does DUSP10 regulate innate immune responses?

DUSP10 serves as a critical negative regulator of innate immune activation. In neutrophils, DUSP10 negatively regulates the inflammatory response by inhibiting NADPH oxidase activity, thereby limiting reactive oxygen species (ROS) production . In macrophages, particularly alveolar macrophages, DUSP10 suppresses the production of pro-inflammatory cytokines (IL-6, TNF-α), chemokines (MIP-2), nitric oxide (NO), and ROS in response to LPS stimulation . This regulatory function helps prevent excessive inflammatory damage during infections and other inflammatory conditions.

What is the role of DUSP10 in adaptive immunity and T cell function?

DUSP10 negatively regulates both Type 1 (IFN-γ) and Type 2 (TNF-α) cytokine expression in effector CD4+ and CD8+ T cells by reducing AP-1 expression through JNK activity regulation . In Th2 cells, particularly the pathogenic ST2hi memory-type Th2 cells involved in eosinophilic airway inflammation, DUSP10 expression constrains IL-33-induced cytokine production . This regulation occurs through the dephosphorylation and inactivation of p38 MAPK, which in turn reduces GATA3 transcription factor activity, a master regulator of Th2 cytokine production .

How does DUSP10 contribute to immune-related disease pathogenesis?

DUSP10's role in immune regulation means its dysfunction can contribute to various immune-related pathologies. In allergic asthma, DUSP10 expression in ST2hi pathogenic Th2 cells helps control cytokine production and potentially limit inflammatory damage . In models of sepsis-induced lung injury, DUSP10 deficiency leads to increased production of pro-inflammatory mediators, although this can paradoxically improve resistance to LPS-induced sepsis . In autoimmune conditions, DUSP10-deficient mice show resistance to experimental autoimmune encephalitis (EAE), suggesting DUSP10 may promote certain autoimmune pathologies by limiting excessive T-cell responses to pathogens .

What is the role of DUSP10 in cancer development and progression?

DUSP10 demonstrates complex roles in cancer, with evidence pointing toward primarily pro-tumorigenic functions. In lower-grade glioma (LGG), DUSP10 is unconventionally upregulated, and higher DUSP10 expression correlates with poorer prognosis . DUSP10 has been verified as an independent prognostic indicator in LGG patients . In several other cancer types, DUSP10 expression is also elevated and associated with poorer outcomes . The mechanism appears to involve DUSP10's effects on cellular proliferation, as demonstrated by in vitro studies in LGG .

How is DUSP10 expression altered in different human cancers?

DUSP10 expression is abnormally elevated in several cancer types, including lower-grade glioma, hepatocellular carcinoma, and pancreatic cancer . In these contexts, various microRNAs (including miR-181 in hepatocellular cancer and miR-92a in pancreatic cancer) that normally suppress DUSP10 expression may be dysregulated, contributing to altered DUSP10 levels . The prognostic significance of DUSP10 overexpression appears consistent across multiple tumor types, suggesting a common mechanism of action in cancer pathogenesis .

How do researchers reconcile contradictory findings regarding DUSP10's regulatory effects in different cell types?

Contradictory findings regarding DUSP10's regulatory effects likely stem from cell type-specific signaling contexts and varying experimental conditions. For instance, DUSP10's regulation by MAPKs shows inconsistent patterns across studies, possibly due to different cell types used . To reconcile these contradictions, researchers should employ comparative analyses across multiple cell types under standardized conditions, use complementary in vitro and in vivo models, and consider the influence of microenvironmental factors on DUSP10 function. Single-cell analysis technologies may help resolve cell type-specific effects that get obscured in bulk tissue studies.

What technological advances are needed to better characterize DUSP10's substrate specificity in vivo?

Current understanding of DUSP10's substrate specificity primarily comes from in vitro studies or indirect cellular assays. Advanced methods needed include: (1) Proximity-based labeling approaches (BioID, APEX) to identify physiological DUSP10 interactors; (2) Phosphoproteomic analysis comparing wild-type and DUSP10-deficient cells to comprehensively map affected phosphorylation sites; (3) Development of substrate-trapping DUSP10 mutants that bind but do not dephosphorylate targets; and (4) Cellular FRET-based sensors to monitor DUSP10 activity in real-time and in specific subcellular compartments.

What are the implications of DUSP10's dual roles in cancer and inflammation for targeted therapeutic development?

DUSP10's apparently opposing roles in cancer (pro-tumorigenic) and inflammation (anti-inflammatory) present a therapeutic paradox that requires careful consideration in drug development. Potential strategies to navigate this complexity include: (1) Developing tissue-specific delivery approaches to target DUSP10 modulation only in desired tissues; (2) Exploiting differential expression or activity patterns of DUSP10 in cancer versus inflamed non-cancerous tissues; (3) Identifying pathway-specific modulators that affect only certain DUSP10 functions while sparing others; and (4) Considering combination therapies that can mitigate undesired effects of DUSP10 targeting. The available data suggests DUSP10 represents an attractive therapeutic target, but requires sophisticated approaches to navigate its context-dependent roles .