LERK‑3 (Ephrin‑A3 / EFNA3): GPI‑Anchored Ephrin Ligand for Bidirectional Signaling Mechanism Research

Modular Molecular Architecture and Glycosylation‑Dependent Protein Properties

LERK‑3, also annotated Ephrin‑A3 or EFNA3, represents a GPI‑anchored cell‑surface glycoprotein belonging to the Ephrin‑A ligand protein family. Recombinant LERK‑3 constructs are commonly generated via HEK293 mammalian expression platforms, frequently fused with C‑terminal His‑tags to streamline affinity‑purification workflows. Four discrete functional modules constitute the full‑length primary polypeptide sequence. An N‑terminal signal peptide directs nascent polypeptide trafficking toward plasma membrane compartments; a ~20 kDa conserved Ephrin domain mediates high‑affinity physical contacts with EPHA‑subfamily receptor tyrosine kinases. A cysteine‑enriched GPI‑anchor segment enables stable membrane tethering, while an inter‑domain flexible linker supports conformational adjustments for distinct receptor‑subtype complexes. Multiple N‑linked glycosylation acceptor sites such as Asn‑32 and Asn‑65 introduce glycan modifications that improve protein stability and tune Eph‑receptor binding affinity parameters. Cryo‑EM structural investigations resolve a characteristic groove‑shaped receptor‑binding interface that forms steric complementary surfaces with the EphA8 ligand‑binding ectodomain.

Bidirectional Signal‑Transduction Mechanisms Triggered by LERK‑3‑Eph Receptor Engagement

LERK‑3‑Eph‑receptor molecular complexes initiate well‑documented bidirectional signaling cascades across adjacent contacting cell populations. Forward signaling denotes intracellular responses occurring within Eph‑receptor‑expressing target cells after ligand‑receptor ligation. Downstream Rho‑GTPase effector activation drives actin cytoskeleton rearrangement to regulate neuronal axon guidance and endothelial‑cell migratory behaviors. Reverse signaling proceeds within LERK‑3‑presenting cells despite the absence of canonical intracellular polypeptide segments from this GPI‑tethered molecule. Membrane‑receptor clustering recruits PDZ‑domain‑containing adaptor molecules to activate Src‑kinase and PI3K‑AKT signal‑transduction axes. These reverse‑signaling outputs modulate cell‑to‑cell adhesive interactions and determine cell survival thresholds under diverse in‑vitro culture and in‑vivo tissue microenvironment contexts.

Multifaceted Physiological Roles in Neurodevelopment and Angiogenesis

During vertebrate neural‑tissue formation, LERK‑3‑dependent repulsive molecular cues steer neural‑crest‑cell directional migration patterns for proper dorsal‑spinal‑cord neuronal‑circuit assembly. This ligand exhibits dose‑dependent regulatory properties controlling vascular endothelial‑cell biological outputs within angiogenesis experimental systems. Low LERK‑3 concentrations support endothelial‑cell proliferative responses, whereas elevated ligand concentrations trigger programmed apoptotic cell death within endothelial cell populations. Such bimodal activity supplies mechanistic foundations for investigating pathological neo‑vascularization events across multiple laboratory disease‑model platforms.

Pathological‑Model Research Outcomes for Tumor, Spinal‑Cord Injury and Autoimmunity

Elevated LERK‑3 transcript and protein abundance can be measured in experimental glioblastoma and breast‑cancer cell‑line model systems. Cell‑cell repulsion signals driven by overexpressed LERK‑3 facilitate malignant‑cell detachment from primary tumor sites in metastatic progression assays. Soluble recombinant sEFNA3 protein competes for Eph‑receptor occupancy and significantly lowers pulmonary metastatic burden in melanoma murine models (p < 0.01). When embedded inside biodegradable hydrogel scaffolds, localized sustained LERK‑3 delivery guides regenerating axonal fibers across spinal‑cord‑lesion boundaries and raises motor‑functional‑recovery scores by 42 % in pre‑clinical animal assays. LERK‑3 signaling also restricts pathological Th17 lymphocyte differentiation via EphA4‑receptor modulation. In rheumatoid‑arthritis mouse experimental cohorts, LERK‑3 recombinant‑protein intervention reduces measurable joint‑inflammation scores by 57 % (p = 0.008).

Existing Technical Barriers and Emerging Experimental‑Tool Innovations

Three primary technical hurdles constrain deeper mechanistic exploration of LERK‑3‑associated biological cascades within basic‑research laboratories. Spatiotemporal dynamics governing bidirectional forward‑reverse signaling responses remain incompletely mapped across distinct tissue microenvironments. Systemically administered soluble LERK‑3 recombinant protein displays short circulating half‑life, approximately 2.3 hours, limiting many in‑vivo experimental readouts. Functional redundancy shared amongst Ephrin‑A paralogues complicates phenotypic interpretation from ligand‑perturbation laboratory trials. Nanobody‑engineering workflows reported in Nature Biotechnology deliver one promising mitigation strategy. Phage‑display‑derived anti‑LERK‑3 nanobody clones reach KD = 0.8 nM binding affinity and extend in‑vivo circulation half‑life to 72 hours with enhanced solid‑tissue penetration properties. CRISPR‑Cas9 genome‑editing enables generation of tissue‑restricted LERK‑3‑knockout animal strains for precise cell‑type‑specific functional‑dissection research.

Recombinant Protein & Antibody Reagent Portfolio from ANT BIO PTE. LTD

ANT BIO PTE. LTD provides a diversified panel of recombinant monoclonal antibodies and His‑tagged recombinant protein reagents supporting Eph‑ephrin‑axis mechanistic investigations across structural‑biology, cell‑function and animal‑model workflows. Every reagent lot undergoes multi‑assay functional validation before commercial distribution.

Catalog Table of Eph‑Ephrin‑Axis‑Related Research Reagents

Functional‑Validation Characteristics of ANT BIO PTE. LTD Research Reagents

Recombinant antibody clones pass peptide‑array cross‑reactivity screening to reduce off‑target signal artifacts within complex cell and tissue lysate matrices. The FITC‑conjugated S0B1762 anti‑His‑tag antibody enables direct detection of C‑terminally‑His‑tagged LERK‑3 recombinant protein without secondary‑antibody incubation steps. Mammalian‑cell‑expressed UA011232 serves as reference glycoprotein control for glycosylation‑related experimental setups. Validated experimental workflows cover Western‑blot quantification, immunofluorescence localization, affinity‑purification enrichment and immunoprecipitation‑based protein‑interaction assays.

Core Fundamental‑Research Applications for This Reagent Panel

1. Western‑blot expression quantification for recombinant His‑tagged LERK‑3 protein from HEK293 cell culture supernatant preparations

2. Immunoprecipitation‑coupled LC‑MS/MS assays mapping LERK‑3‑associated Eph‑receptor and intracellular adaptor‑protein interactomes

3. Immunofluorescence cellular imaging observing LERK‑3 subcellular membrane localization under gain‑of‑function or gene‑knockout genetic perturbation

4. Functional cell‑based migration and apoptosis assays testing soluble LERK‑3 ligand dose‑response profiles in endothelial and tumor‑cell‑line cultures

5. Tissue‑microarray immunohistochemical profiling measuring endogenous LERK‑3 abundance in tumor, spinal‑cord and autoimmune‑disease‑model tissue specimens

6. Quality‑control characterization of recombinant Eph‑ephrin ligands for cryo‑EM structural‑biology and in‑vivo animal‑model intervention experiments

Global Manufacturing & Compliance Standards

All antibody and recombinant‑protein batches complete multi‑dimensional functional‑performance verification prior to commercial release. Manufacturing facilities adhere to ISO9001, ISO13485 and EU 98/79/EC certification requirements for life‑science‑research‑reagent production. In‑house application‑science teams supply optimized WB, IP and cell‑functional‑assay SOP documents plus curated Eph‑ephrin‑signaling reference‑publication resources. The complete reagent ecosystem integrates PTM‑detection antibodies, ELISA kits and immuno‑affinity beads for multi‑omics developmental‑biology and cancer‑research pipelines.

ANT BIO PTE. LTD. – Empowering Scientific Breakthroughs
At ANT BIO PTE. LTD., we are committed to advancing life science research through high‑quality, reliable reagents and comprehensive solutions. Our specialized sub‑brands (Absin, Starter, UA) cover a full spectrum of research needs, from general reagents and kits to antibodies and recombinant proteins. With a focus on innovation, quality, and customer‑centricity, we strive to be your trusted partner in unlocking scientific mysteries and driving medical progress. Explore our product portfolio today and elevate your research to new heights.

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