BTN1A1 - butyrophilin subfamily 1 member A1 | Elisa - Clia - Antibody - Protein

Background

Butyrophilin subfamily 1 member A1 (BTN1A1) is a member of the butyrophilin family, which belongs to the immunoglobulin superfamily. The butyrophilin family consists of proteins that play crucial roles in immune regulation and cellular communication. BTN1A1 is primarily known for its role in milk fat globule secretion in mammary epithelial cells and has also been implicated in various immune functions. This protein is of significant interest due to its involvement in both lactation and immune modulation, making it a focal point for studies related to immunology, lactation biology, and related diseases.

Protein Structure

BTN1A1 is a transmembrane glycoprotein characterized by its typical immunoglobulin-like domain structure. The protein comprises the following domains:

1. Extracellular Domain: BTN1A1 has an N-terminal region that contains immunoglobulin-like V-type and C-type domains. These domains facilitate interactions with other proteins and cells.
2. Transmembrane Domain: This hydrophobic domain anchors the protein in the cell membrane, allowing it to function as a receptor or adhesion molecule.
3. Cytoplasmic Tail: The intracellular region of BTN1A1 is involved in intracellular signaling and interaction with cytoplasmic proteins. It is crucial for transmitting signals from the extracellular environment to the cell's interior.

The structural configuration of BTN1A1 enables it to perform its functions effectively, both in immune modulation and the secretion of milk fat globules.

Classification and Subtypes

BTN1A1 is a member of the butyrophilin family, which includes several other proteins categorized based on their sequence homology and functional similarities. The butyrophilin family can be divided into:

1. Classical Butyrophilins (BTN1 and BTN2 Subfamilies): These proteins, including BTN1A1, are primarily involved in immune regulation and cellular interactions.
2. Butyrophilin-like Proteins (BTNLs): These proteins share structural similarities with classical butyrophilins but are primarily involved in modulating immune responses, particularly in mucosal tissues.

Within the BTN1 subfamily, BTN1A1 is the most extensively studied member due to its prominent role in lactation.

Function and Biological Significance

BTN1A1 has two major functional roles:

1. Lactation: BTN1A1 is crucial for the formation and secretion of milk fat globules in the mammary glands. It is involved in the process of encapsulating triglycerides in the mammary epithelial cells and facilitating their secretion into the milk. This function is essential for providing energy-rich nutrients to neonates during breastfeeding.
2. Immune Regulation: BTN1A1 has been implicated in immune modulation. It is expressed in various tissues, including immune cells, and can influence T cell responses. BTN1A1's extracellular domains interact with receptors on immune cells, modulating their activation and function. This role is vital for maintaining immune homeostasis and preventing excessive immune reactions.

Clinical Issues

The dysregulation of BTN1A1 has been linked to several clinical conditions:

1. Lactation Disorders: Mutations or deficiencies in BTN1A1 can lead to impaired milk production or secretion, affecting neonatal nutrition and growth. Understanding BTN1A1's role in lactation can help develop therapeutic interventions for lactation insufficiency.
2. Immune-Related Disorders: Given BTN1A1's role in immune regulation, its aberrant expression or function can contribute to autoimmune diseases and inflammatory conditions. BTN1A1's involvement in T cell modulation suggests it could be a target for immunotherapy in autoimmune diseases and cancer.
3. Breast Cancer: Studies have indicated that BTN1A1 expression is altered in breast cancer tissues. Its role in milk production and mammary gland physiology suggests that it could be involved in tumorigenesis in the mammary glands. Further research is needed to elucidate BTN1A1's potential as a biomarker or therapeutic target in breast cancer.

Summary

BTN1A1 is a multifunctional protein belonging to the butyrophilin family, with significant roles in both lactation and immune regulation. Its structural features, including immunoglobulin-like domains, enable it to perform its functions effectively. BTN1A1's involvement in milk fat globule secretion is critical for neonatal nutrition, while its immune-modulatory functions are vital for maintaining immune homeostasis. Dysregulation of BTN1A1 is associated with various clinical conditions, including lactation disorders, autoimmune diseases, and breast cancer. Understanding BTN1A1's functions and mechanisms can provide insights into developing therapeutic strategies for these conditions.