Actin, Alpha 2, Smooth Muscle, Aorta Human Recombinant
Actin Rabbit
Actin Filament Associated Protein 1 Human Recombinant
Actin Related Protein 2/3 Complex, Subunit 2 Human Recombinant
Actin Related Protein 2/3 Complex, Subunit 3 Human Recombinant
Actin Related Protein 2/3 Complex, Subunit 5 Human Recombinant
Cardiac Actin Bovine
Actin is a highly conserved protein that plays a crucial role in various cellular processes. It is a major component of the cytoskeleton, which provides structural support to cells. Actin exists in two forms: globular actin (G-actin) and filamentous actin (F-actin). G-actin is a monomeric form, while F-actin is a polymerized form that assembles into long, thin filaments. Actin is classified into three main isoforms in vertebrates: alpha (α), beta (β), and gamma (γ) actin. Alpha actin is primarily found in muscle cells, while beta and gamma actin are present in non-muscle cells.
Key Biological Properties: Actin is a highly dynamic protein that can rapidly polymerize and depolymerize, allowing cells to change shape and move. It has ATPase activity, meaning it can hydrolyze ATP to ADP, which is essential for its polymerization.
Expression Patterns: Actin is ubiquitously expressed in all eukaryotic cells, with different isoforms being expressed in specific tissues. For example, α-actin is predominantly expressed in skeletal, cardiac, and smooth muscle cells.
Tissue Distribution: Actin is found in various tissues, including muscle, epithelial, endothelial, and nerve tissues. Its distribution is critical for maintaining cell shape, enabling cell motility, and facilitating intracellular transport.
Primary Biological Functions: Actin is involved in numerous cellular processes, including cell motility, division, and intracellular transport. It forms the structural framework of the cytoskeleton, providing mechanical support to cells.
Role in Immune Responses: Actin plays a vital role in immune cell functions, such as phagocytosis, where immune cells engulf and destroy pathogens. It also participates in the formation of the immunological synapse, a specialized junction between immune cells that facilitates communication and activation.
Pathogen Recognition: Actin dynamics are crucial for the recognition and internalization of pathogens by immune cells. Actin remodeling allows immune cells to extend pseudopodia and engulf pathogens through phagocytosis.
Mechanisms with Other Molecules and Cells: Actin interacts with various proteins, including actin-binding proteins (ABPs), which regulate its polymerization and depolymerization. These interactions are essential for the formation of actin filaments and networks.
Binding Partners: Actin binds to numerous proteins, such as myosin, tropomyosin, and profilin. Myosin motors interact with actin filaments to generate contractile forces, while tropomyosin stabilizes actin filaments. Profilin promotes actin polymerization by binding to G-actin.
Downstream Signaling Cascades: Actin dynamics are regulated by signaling pathways, such as the Rho family of GTPases. These pathways control actin polymerization and depolymerization, influencing cell shape, motility, and division.
Expression and Activity: Actin expression is tightly regulated at the transcriptional level by various transcription factors. Post-transcriptional mechanisms, such as mRNA stability and translation, also play a role in controlling actin levels.
Transcriptional Regulation: Transcription factors, such as serum response factor (SRF), bind to specific DNA sequences in the actin gene promoter, regulating its transcription. SRF activity is modulated by signaling pathways, including the MAPK pathway.
Post-Translational Modifications: Actin undergoes various post-translational modifications, such as phosphorylation, acetylation, and ubiquitination. These modifications can affect actin’s polymerization, stability, and interactions with other proteins.
Biomedical Research: Actin is widely studied in biomedical research due to its fundamental role in cellular processes. It serves as a model protein for understanding cytoskeletal dynamics and cell motility.
Diagnostic Tools: Actin antibodies are used in immunohistochemistry to detect actin expression in tissues. Abnormal actin expression patterns can be indicative of certain diseases, such as cancer.
Therapeutic Strategies: Targeting actin dynamics is a potential therapeutic strategy for various diseases. For example, actin-targeting drugs are being explored for their potential to inhibit cancer cell migration and metastasis.
Development: Actin is essential for embryonic development, as it regulates cell division, migration, and differentiation. Actin dynamics are crucial for the formation of tissues and organs during development.
Aging: Actin undergoes age-related changes, such as increased oxidation and decreased polymerization. These changes can affect cellular functions, contributing to the aging process.
Disease: Abnormal actin dynamics are associated with various diseases, including cancer, neurodegenerative disorders, and cardiovascular diseases. Understanding actin’s role in these diseases can provide insights into potential therapeutic targets.
Actin is a versatile and dynamic protein that plays a central role in numerous cellular processes. Its regulation and interactions with other molecules are critical for maintaining cellular functions and overall organismal health. Ongoing research continues to uncover new insights into actin’s functions and its potential applications in medicine.