{"product_id":"recombinant-human-papillomavirus-type-16-protein-e4-e4-bhp10507492","title":"Recombinant Human papillomavirus type 16 protein E4 (E4)","description":"\u003ch2\u003eOverview\u003c\/h2\u003e\u003cp\u003eThis Recombinant Protein provides recombinant \u003cstrong\u003eE4\u003c\/strong\u003e from Human papillomavirus type 16, produced in E.coli (region 1-92aa). It is commonly used as a defined reagent for assay development, binding studies, and mechanistic research (RUO).\u003c\/p\u003e\u003ch2\u003eKey elements and design rationale\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eRegion:\u003c\/strong\u003e 1-92aa (domain boundaries can affect binding\/activity readouts).\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eExpression host:\u003c\/strong\u003e E.coli (may differ from native PTMs\/processing).\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTag(s):\u003c\/strong\u003e His, Myc (supports purification\/detection; consider tag effects in controls).\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eBiological background\u003c\/h2\u003e\u003cp\u003eAlso reported as E1^E4. Contributes to multiple aspects of the viral life cycle including viral genome amplification, suppression of suprabasal cell differentiation and egress of newly formed virions. Induces host cell cycle arrest at the G2 phase by associating with and preventing the nuclear entry of host CDK1\/cyclin B1 complexes. Inhibits cellular DNA replication by preventing loading of host replication licensing proteins MCM2 and MCM7 onto chromatin. Within the cytoplasm, associates with host kinase SRPK1, a splicing factor regulator, and inhibits its activity. Therefore, E4 favors expression of late viral transcripts by inhibiting SRPK1-mediated phosphorylation of host serine-arginine proteins that have critical roles in mRNA metabolism. Late in the infectious cycle, E4 also acts to diminish the integrity of the keratinocyte by disrupting the keratin cytoskeleton and inducing apoptosis through alteration of mitochondrial function to facilitate egress of the newly formed virions.\u003c\/p\u003e\u003ch2\u003eResearch relevance and current trends\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eActivity assay development for kinetics, substrate scope, and inhibitor\/activator profiling.\u003c\/li\u003e\n\u003cli\u003eUse of recombinant standards to improve assay calibration and cross-study comparability.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eContributes to multiple aspects of the viral life cycle including viral genome amplification, suppression of suprabasal cell differentiation and egress of newly formed virions. Induces host cell cycle arrest at the G2 phase by associating with and preventing the nuclear entry of host CDK1\/cyclin B1 complexes. Inhibits cellular DNA replication by preventing loading of host replication licensing proteins MCM2 and MCM7 onto chromatin. Within the cytoplasm, associates with host kinase SRPK1, a splicing factor regulator, and inhibits its activity. Therefore, E4 favors expression of late viral transcripts by inhibiting SRPK1-mediated phosphorylation of host serine-arginine proteins that have critical roles in mRNA metabolism. Late in the infectious cycle, E4 also acts to diminish the integrity of the keratinocyte by disrupting the keratin cytoskeleton and inducing apoptosis through alteration of mitochondrial function to facilitate egress of the newly formed virions.\u003c\/p\u003e\u003ch2\u003eCommon research applications\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eStandard curve or spike-in reference for quantitative assays involving E4\u003c\/li\u003e\n\u003cli\u003eEnzymatic activity measurements with defined substrates\/cofactors (assay-dependent)\u003c\/li\u003e\n\u003cli\u003eCompound screening using concentration–response concepts (assay-dependent)\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eNotes for experimental interpretation\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eRecombinant constructs may not capture all native isoforms or PTMs.\u003c\/li\u003e\n\u003cli\u003eConsider tag- or host-related effects when interpreting binding or activity.\u003c\/li\u003e\n\u003cli\u003eUse appropriate blanks and matrix\/control concepts to separate signal from background.\u003c\/li\u003e\n\u003c\/ul\u003e\u003c!-- Sources (internal): - UniProtKB P06922 — UniProt — https:\/\/www.uniprot.org\/uniprotkb\/P06922 - NCBI Gene search: E4 — NCBI — https:\/\/www.ncbi.nlm.nih.gov\/gene\/?term=E4 - Ensembl search: E4 — Ensembl — https:\/\/www.ensembl.org\/Multi\/Search\/Results?q=E4 - Reactome Pathway Browser — Reactome — https:\/\/reactome.org\/ - NCBI Bookshelf — NCBI — https:\/\/www.ncbi.nlm.nih.gov\/books\/ --\u003e","brand":"CUSABIO TECHNOLOGY LLC","offers":[{"title":"1 mg","offer_id":53053414408557,"sku":"CSB-EP356968HML-1MG","price":2466.0,"currency_code":"USD","in_stock":true},{"title":"100 ug","offer_id":53053550133613,"sku":"CSB-EP356968HML-100UG","price":729.0,"currency_code":"USD","in_stock":true},{"title":"20 ug","offer_id":53053550166381,"sku":"CSB-EP356968HML-20UG","price":388.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0949\/7424\/7277\/files\/CSB-EP356968HML-1.jpg?v=1772177678","url":"https:\/\/www.ebiohippo.com\/products\/recombinant-human-papillomavirus-type-16-protein-e4-e4-bhp10507492","provider":"BioHippo","version":"1.0","type":"link"}