Recombinant Proteins
Product List
SAR1A Human
GTP-Binding Protein SAR1A Human Recombinant
The SAR1A is purified by proprietary chromatographic techniques.
SAR1B Human
GTP-Binding Protein SAR1B Human Recombinant
SAR1B is fused to a 23 amino acid His-tag at N-terminus & purified by proprietary chromatographic techniques.
Introduction
GTP-binding proteins, also known as G-proteins, are a family of proteins that bind guanosine triphosphate (GTP) and guanosine diphosphate (GDP). These proteins play a crucial role in transmitting signals from various stimuli outside a cell to its interior. GTP-binding proteins are classified into two main categories:
- Heterotrimeric G-proteins: Composed of three subunits (alpha, beta, and gamma), these proteins are associated with cell surface receptors known as G-protein-coupled receptors (GPCRs).
- Small GTPases: These are monomeric proteins that include members of the Ras, Rho, Rab, Arf, and Ran families.
Key Biological Properties: GTP-binding proteins exhibit intrinsic GTPase activity, allowing them to hydrolyze GTP to GDP. This activity is essential for their role as molecular switches in signaling pathways.
Expression Patterns: The expression of GTP-binding proteins varies widely among different cell types and tissues. For example, heterotrimeric G-proteins are ubiquitously expressed, while small GTPases may have more specific expression patterns.
Tissue Distribution: GTP-binding proteins are found in virtually all tissues, with high concentrations in the brain, immune cells, and endocrine tissues. Their distribution is closely linked to their functional roles in various physiological processes.
Primary Biological Functions: GTP-binding proteins are involved in a wide range of cellular processes, including cell growth, differentiation, and movement. They act as molecular switches that toggle between active (GTP-bound) and inactive (GDP-bound) states.
Role in Immune Responses: GTP-binding proteins play a pivotal role in the immune system by regulating the activation and migration of immune cells. For instance, small GTPases like Rac and Rho are crucial for the formation of the immune synapse and phagocytosis.
Pathogen Recognition: Certain GTP-binding proteins are involved in recognizing and responding to pathogens. For example, the GTPase Rac1 is activated in response to bacterial infection, leading to the production of reactive oxygen species (ROS) that help eliminate the pathogen.
Mechanisms with Other Molecules and Cells: GTP-binding proteins interact with a variety of effector molecules, including enzymes, ion channels, and other signaling proteins. These interactions are often mediated by specific binding domains that recognize the active (GTP-bound) form of the protein.
Binding Partners: GTP-binding proteins have numerous binding partners, such as guanine nucleotide exchange factors (GEFs) that facilitate the exchange of GDP for GTP, and GTPase-activating proteins (GAPs) that enhance their intrinsic GTPase activity.
Downstream Signaling Cascades: Upon activation, GTP-binding proteins initiate a cascade of downstream signaling events. For example, the activation of heterotrimeric G-proteins by GPCRs leads to the production of second messengers like cyclic AMP (cAMP) and inositol trisphosphate (IP3), which further propagate the signal within the cell.
Regulatory Mechanisms that Control Expression and Activity: The expression and activity of GTP-binding proteins are tightly regulated at multiple levels, including transcriptional, post-transcriptional, and post-translational mechanisms.
Transcriptional Regulation: The genes encoding GTP-binding proteins are subject to regulation by various transcription factors that respond to extracellular signals. For example, the expression of certain small GTPases is upregulated in response to growth factors.
Post-Translational Modifications: GTP-binding proteins undergo various post-translational modifications, such as phosphorylation, ubiquitination, and prenylation. These modifications can influence their localization, stability, and interaction with other proteins.
Biomedical Research: GTP-binding proteins are extensively studied in biomedical research due to their central role in cell signaling. They serve as important models for understanding the molecular basis of diseases and developing targeted therapies.
Diagnostic Tools: Abnormalities in GTP-binding protein signaling are associated with various diseases, including cancer and neurodegenerative disorders. As such, these proteins are valuable biomarkers for diagnostic purposes.
Therapeutic Strategies: Targeting GTP-binding proteins and their regulatory pathways holds promise for therapeutic interventions. For example, inhibitors of specific small GTPases are being explored as potential treatments for cancer and inflammatory diseases.
Role Throughout the Life Cycle: GTP-binding proteins play critical roles throughout the life cycle, from development to aging and disease. During development, they regulate processes such as cell proliferation, differentiation, and migration.
Aging and Disease: Dysregulation of GTP-binding protein signaling is implicated in aging and age-related diseases. For instance, mutations in the Ras family of small GTPases are commonly found in cancers, while alterations in G-protein signaling are linked to neurodegenerative disorders like Alzheimer’s disease.
In summary, GTP-binding proteins are essential regulators of cellular signaling with diverse roles in physiology and pathology. Their study continues to provide valuable insights into the molecular mechanisms underlying health and disease.
