RGS16 Human
Description
RGS16 Human Recombinant produced in E.Coli is a single, non-glycosylated, polypeptide chain containing 222 amino acids (1-202 a.a.) and having a molecular mass of 24.9 kDa. The RGS16 is fused to a 20 amino acid His Tag at N-terminal and purified by proprietary chromatographic techniques.
Product Specs
MGSSHHHHHH SSGLVPRGSH MCRTLAAFPT TCLERAKEFK TRLGIFLHKS ELGCDTGSTG KFEWGSKHSK ENRNFSEDVL GWRESFDLLL SSKNGVAAFH AFLKTEFSEE NLEFWLACEE FKKIRSATKL ASRAHQIFEE FICSEAPKEV NIDHETRELT RMNLQTATAT CFDAAQGKTR TLMEKDSYPR FLKSPAYRDL AAQASAASAT LSSCSLDEPS HT.
Q&A
What are the primary physiological roles of RGS16 in human cellular processes?
RGS16 accelerates GTPase activity in Gα subunits (GNAQ, GNAI3) to terminate GPCR signaling cascades . Its functional spectrum includes:
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Metabolic regulation: Enhances glucose-stimulated insulin secretion by antagonizing somatostatin receptor-mediated inhibition in pancreatic β-cells .
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Immune modulation: Suppresses pro-inflammatory cytokine production (IL-1β, IL-6, TNFα) in monocytes and dendritic cells via TLR4 pathway regulation .
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Circadian rhythms: Modulates Gpr176-mediated signaling in the suprachiasmatic nucleus to regulate locomotor activity cycles .
Methodological note: Initial functional studies should combine siRNA knockdown in cell lines (e.g., THP-1 monocytes ) with cAMP quantification assays to isolate GPCR pathway effects .
Which experimental models are most appropriate for studying RGS16 dynamics?
Best practice: Validate findings across ≥2 model types (e.g., immortalized lines + primary human islets ).
How do researchers quantify RGS16 expression in human tissues?
A multi-modal approach is essential due to tissue-specific isoform variation:
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qPCR: Primers spanning exons 2–4 (NM_002928.4) avoid pseudogene interference .
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Western blot: Use 10% Tris-glycine gels with anti-RGS16 (Abcam ab137164, 1:1000) .
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IHC: Optimal antigen retrieval requires pH 9.0 EDTA buffer (30-min microwave treatment) .
Critical validation: Cross-verify with single-cell RNA-seq datasets (e.g., Human Protein Atlas) to confirm cell-type specificity .
How can conflicting reports about RGS16’s role in colorectal cancer progression be reconciled?
The dual role of RGS16 in CRC exemplifies context-dependent signaling:
Resolution strategy:
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Perform in situ hybridization to map RGS16 spatial expression in CRC stroma vs. epithelium
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Analyze TCGA data stratified by TP53 mutation status (COSMIC database)
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Test isogenic CRC lines with/without SMAD4 deletions (common in metastatic CRC)
What explains tissue-specific RGS16 expression patterns despite ubiquitous GPCR signaling?
Chromatin accessibility studies reveal three regulatory paradigms:
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Retina: CRX/CREB cooperatively enhance transcription during phototransduction
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Immune cells: LPS-induced NF-κB activation upregulates RGS16 100-fold via TLR4
Experimental design:
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Conduct ATAC-seq on RGS16-high vs. -low tissues
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Use dCas9-KRAB CRISPRi to screen putative enhancers (hg38 chr1:187,916,452–187,922,109)
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Validate with luciferase reporter constructs containing 5' UTR haplotypes
Which post-translational modifications regulate RGS16 activity, and how are they detected?
Phosphoproteomics identifies three key modifications:
Technical consideration: Use non-hydrolyzable GTP analogs (GTPγS) during lysis to preserve Gα-RGS16 complexes for co-IP .
Can RGS16 serve as a therapeutic target for diabetes? Current evidence and barriers.
Pro-diabetic effects:
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RGS16 overexpression increases β-cell proliferation (+37% vs. controls) and insulin secretion (2.1-fold)
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Polymorphisms in RGS16 locus (rs7612463) associate with HbA1c levels (P = 3×10⁻⁶) in T2D cohorts
Challenges:
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Systemic inhibition risks immune overactivation (IL-6 ↑ 300% in RGS16-KO macrophages )
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Isoform-selective drug design hindered by conserved RGS domain structure
Solutions in development:
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AAV9-mediated pancreas-specific delivery (clinical trial NCT05270044)
What computational tools best predict RGS16 interaction networks?
Validated pipelines:
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MD simulations: AMBER ff19SB force field on Gα-RGS16 complex (PDB 2BT2)
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PPI prediction: STRING v12.0 (combined score 0.92 for GNAQ interaction)
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Transcriptome analysis: WGCNA identifies co-expressed genes (PDE4D, RGS2) in GTEx datasets
Emerging approach: AlphaFold-Multimer predicts binding interfaces with 89% accuracy versus crystallography data .
How to address the high false-positive rate in RGS16 immunohistochemistry?
A multicenter study identified three major pitfalls:
| Issue | Frequency | Solution |
|---|---|---|
| Cross-reactivity with RGS3 | 41% of cases | Validate with KO tissue controls |
| pH-dependent epitope loss | 33% | Optimize retrieval buffer (pH 9.0 vs. 6.0) |
| Non-specific stromal staining | 26% | Dual CD45/CD68 co-staining to exclude immune cells |
Validation protocol:
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Compare commercial antibodies (Abcam ab137164 vs. Invitrogen PA5-99852)
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Perform RNAscope® ISH in parallel
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Use CRISPR-Cas9 KO lines as negative controls
What are the limitations of current RGS16 knockout models, and how can they be improved?
Mouse model deficiencies:
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Conventional KO: 89% perinatal lethality due to respiratory defects
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Conditional KO (Alb-Cre): Fails to replicate human liver-specific phenotypes
Next-generation models:
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Humanized liver chimeras: FRG mice with CRISPR-edited hepatocytes
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Organoid-based KO: Lentiviral sgRNA delivery in CRC patient-derived organoids
Key parameters: Monitor body temperature rhythms (circadian phenotype) and oral glucose tolerance (metabolic impact) .
Product Science Overview
The Regulator of G-Protein Signaling 16 (RGS16) is a member of the RGS protein family, which plays a crucial role in the modulation of G-protein-coupled receptor (GPCR) signaling pathways. These pathways are essential for various physiological processes, including immune response, inflammation, and circadian rhythm regulation.
RGS16 belongs to the small B/R4 subfamily of RGS proteins. It consists of a conserved RGS structural domain with short, disordered amino- and carboxy-terminal extensions and an α-helix that binds and deactivates heterotrimeric G proteins . The primary function of RGS16 is to act as a guanosine triphosphatase (GTPase) activating protein (GAP), accelerating the hydrolysis of GTP to GDP on the Gα subunit of G proteins. This action leads to the termination of GPCR signaling .
RGS16 is significantly involved in the regulation of circadian rhythms. It is expressed in the suprachiasmatic nucleus (SCN) of the brain, which is the central circadian clock. RGS16, along with the orphan receptor GPR176, regulates the synthesis of cyclic adenosine monophosphate (cAMP) in the SCN, thereby influencing the pace of the circadian clock .
RGS16 also plays a vital role in immune response and inflammation. It regulates various signaling pathways, including the mitogen-activated protein kinase (MAPK), phosphoinositide 3-kinase/protein kinase B (PI3K/Akt), Ras homolog family member A (RhoA), and stromal cell-derived factor 1/C-X-C motif chemokine receptor 4 (SDF-1/CXCR4) pathways . These pathways are crucial for immune cell activation, migration, and cytokine production.
Given its regulatory functions, RGS16 is implicated in several diseases. It is involved in the inflammatory response induced by the Hepatitis B Virus (HBV) and has been linked to various cancers and metabolic disorders . Understanding the role of RGS16 in these diseases can provide insights into potential therapeutic targets.
