GPR101 Antibody

GPR101 Receptor Overview

GPR101 (G Protein-Coupled Receptor 101) is a membrane protein belonging to the G protein-coupled receptor family. The receptor is expressed on various cell types, particularly on human and mouse peripheral blood leukocytes . GPR101 has a molecular weight of approximately 56 kDa and is implicated in several physiological processes . The protein is expected to play an important role in hypothalamic control of energy homeostasis, with duplication of the GPR101 gene linked to X-linked conditions . Understanding the structure, function, and expression patterns of GPR101 has been facilitated by the development of specific antibodies targeting different regions of this receptor.

Definition and Purpose of GPR101 Antibodies

GPR101 antibodies are immunoglobulins specifically designed to recognize and bind to the GPR101 receptor protein. These antibodies are developed through immunization of host animals (typically rabbits) with synthetic peptides derived from different regions of the human GPR101 protein sequence . They serve as essential tools for detecting, quantifying, and studying the localization and function of GPR101 in various biological systems. These antibodies enable researchers to investigate receptor expression patterns, protein-protein interactions, and signaling pathways associated with GPR101, contributing significantly to our understanding of its biological roles in normal physiology and disease states.

Target Regions and Binding Specificity

GPR101 antibodies are designed to target various domains of the receptor, with specific products focusing on:

1. Amino acids 451-500 of the human GPR101 protein

2. Cytoplasmic domain, particularly the third cytoplasmic loop

3. C-terminal region of the protein

4. N-terminal region (amino acids 1-100 or 20-120)

This diversity in target regions allows for comprehensive analysis of GPR101 expression and function across different experimental contexts. The binding specificity is often confirmed through techniques such as BLAST analysis, which ensures minimal cross-reactivity with other human proteins .

Species Reactivity and Cross-Reactivity

GPR101 antibodies exhibit varying degrees of species reactivity, which is an important consideration when designing experiments. Most commercially available antibodies demonstrate reactivity with human GPR101 . Some products also cross-react with GPR101 from other species, including:

1. Mouse GPR101

2. Primate GPR101 (Chimpanzee, Gorilla, Monkey, Marmoset) with 94% identity

3. Orangutan GPR101 (88% identity)

4. Gibbon GPR101 (82% identity)

5. Rat GPR101 (in some antibodies)

This cross-species reactivity is particularly valuable for translational research involving animal models, allowing researchers to draw comparisons between human and animal studies.

Western Blotting

Western blotting represents one of the primary applications for GPR101 antibodies. These antibodies can effectively detect endogenous levels of GPR101 protein in cell and tissue lysates . The recommended dilution ratios typically range from 1:500 to 1:1000 for optimal results . GPR101 antibodies have been validated for Western blot applications using cell lines such as HEK293 human embryonic kidney cells, comparing non-transfected and GPR101-transfected samples to confirm specificity . This application is particularly useful for quantifying GPR101 expression levels and determining changes in response to various experimental conditions.

Immunohistochemistry

GPR101 antibodies are extensively used in immunohistochemistry (IHC) to visualize the distribution and localization of GPR101 within tissue sections . These antibodies are compatible with various sample preparation methods, including:

1. Paraffin-embedded tissue sections (IHC-P)

2. Frozen tissue sections (IHC-F)

3. Cell cultures (ICC)

The ability to detect GPR101 in different sample types provides flexibility in experimental design and allows researchers to study receptor distribution across diverse tissue types and experimental contexts.

Immunofluorescence

Immunofluorescence represents another major application of GPR101 antibodies, allowing for the visualization of receptor localization at the cellular and subcellular levels . GPR101 antibodies used for immunofluorescence are typically diluted at ratios ranging from 1:100 to 1:500 . This technique enables researchers to study:

1. Subcellular localization of GPR101

2. Co-localization with other proteins

3. Trafficking and internalization of the receptor

4. Receptor expression in various cell types

The high specificity of these antibodies ensures reliable detection and minimal background staining in immunofluorescence applications.

ELISA and Other Applications

In addition to the applications mentioned above, GPR101 antibodies are suitable for enzyme-linked immunosorbent assay (ELISA) at recommended dilution ratios of approximately 1:1000 . Other applications include flow cytometry for detecting GPR101 on cell surfaces and immunoprecipitation for isolating GPR101 and its interacting partners . The versatility of these antibodies across multiple experimental platforms makes them valuable tools for comprehensive investigation of GPR101 biology.

Role in Inflammation Resolution

Recent research has revealed a fundamental role for GPR101 in mediating pro-resolving actions in inflammation. GPR101 has been identified as a receptor for RvD5n-3 DPA (Resolvin D5 from n-3 docosapentaenoic acid), an endogenous lipid mediator involved in resolving inflammation . Studies have demonstrated that RvD5n-3 DPA binds to GPR101 with an affinity within its bioactive range, initiating signaling pathways that promote inflammation resolution .

Knockdown of GPR101 in mouse models leads to abrogation of the protective actions of RvD5n-3 DPA, highlighting the essential role of this receptor-ligand interaction . This discovery establishes GPR101 as a potential therapeutic target for inflammatory conditions and underscores the importance of GPR101 antibodies in studying these processes.

Effects on Leukocyte Function

GPR101 mediates various protective actions on leukocytes, particularly neutrophils and monocytes . Research utilizing GPR101 antibodies has demonstrated that activation of this receptor by RvD5n-3 DPA leads to:

1. Regulation of neutrophil trafficking to sites of inflammation

2. Reduction in neutrophil migration toward inflammatory mediators such as leukotriene B4 (LTB4)

3. Decreased transmigration of neutrophils through activated endothelial cell monolayers

4. Enhanced bacterial phagocytosis by both neutrophils and monocytes

5. Accelerated resolution of infectious inflammation

These findings highlight the importance of GPR101 in regulating immune cell functions and its potential as a target for developing new approaches to manage inflammatory diseases.

Antiarthritic Properties

GPR101 has demonstrated antiarthritic properties through its interaction with RvD5n-3 DPA. In mouse models of inflammatory arthritis, activation of GPR101 by RvD5n-3 DPA led to significant reduction in clinical scores compared to vehicle-treated mice . This protective effect was eliminated when GPR101 was knocked down, confirming the receptor's role in mediating these antiarthritic actions .

The identification of GPR101 as a mediator of antiarthritic effects suggests potential therapeutic applications in rheumatoid arthritis and other inflammatory joint diseases, further emphasizing the value of GPR101 antibodies as research tools in this field.

Current Research Status

GPR101 antibodies have significantly advanced our understanding of GPR101 expression, localization, and function across various biological contexts. These antibodies have facilitated research demonstrating GPR101's role in inflammation resolution, leukocyte function regulation, and protection against inflammatory arthritis . The continued development and characterization of specific and sensitive GPR101 antibodies will further enhance our ability to investigate this receptor's biology and potential therapeutic applications.

Future Research Directions

Future research utilizing GPR101 antibodies is likely to focus on several promising directions:

1. Further characterization of GPR101 expression patterns across different tissues and cell types

2. Investigation of GPR101 signaling pathways and their regulation

3. Exploration of additional ligands for GPR101 beyond RvD5n-3 DPA

4. Development of therapeutic approaches targeting GPR101 for inflammatory diseases

5. Study of GPR101's role in energy homeostasis and metabolic disorders

6. Investigation of the relationship between GPR101 and various pathological conditions