CADM - cell adhesion molecule | Elisa - Clia - Antibody - Protein

Background

Cell adhesion molecules (CADMs) are critical components in the regulation of cellular interactions and the maintenance of tissue architecture. CADMs belong to the immunoglobulin superfamily, which encompasses various proteins involved in immune responses and cell adhesion processes. These molecules play pivotal roles in embryonic development, tissue repair, immune responses, and the suppression of tumor progression. CADMs are widely expressed in epithelial tissues, the nervous system, and the immune system, facilitating a range of cellular functions from signal transduction to maintaining cell polarity and tissue integrity.

Protein Structure

CADMs are characterized by their typical protein structure, which includes:

• Extracellular Domain: Composed of three immunoglobulin-like (Ig-like) domains that facilitate homophilic (same molecule) and heterophilic (different molecules) interactions.
• Transmembrane Segment: A single-pass transmembrane region that anchors the protein to the cell membrane.
• Cytoplasmic Tail: Contains binding sites for intracellular signaling molecules and the cytoskeleton, interacting with scaffold proteins like membrane-associated guanylate kinase (MAGUK) proteins.

Classification and Subtypes

CADMs are classified based on their genetic and functional characteristics. The main subtypes include:

1. CADM1 (TSLC1): Involved in cell adhesion, neural development, and tumor suppression. Highly expressed in epithelial cells and the nervous system.
2. CADM2 (IGSF4D): Predominantly found in the nervous system, contributing to synaptic adhesion and neural network formation.
3. CADM3 (Necl-1, IGSF4C): Also primarily expressed in neural tissues, important for synapse formation and maintenance.
4. CADM4 (Necl-4, IGSF4B): Found in various tissues including the nervous system and epithelial cells, playing a role in cell adhesion and signaling.

Function and Biological Significance

CADMs have several crucial functions:

• Cell-Cell Adhesion: They mediate stable cell-cell interactions crucial for maintaining tissue architecture and cellular communication.
• Tumor Suppression: CADMs inhibit tumor growth and metastasis by maintaining normal cell adhesion properties and signaling pathways. Loss of CADM expression is often associated with increased tumor invasiveness.
• Neural Development: In the nervous system, CADMs are essential for the formation and stabilization of synaptic contacts, impacting learning and memory.
• Immune Response: CADMs contribute to immune surveillance by facilitating interactions between immune cells and target cells.

Clinical Issues

Alterations in CADM expression or function are linked to various clinical conditions:

• Cancer: Loss of CADM1 expression is frequently observed in lung, breast, and prostate cancers, highlighting its role as a tumor suppressor.
• Neurological Disorders: Mutations or altered expression of CADMs can lead to developmental disorders and diseases such as autism and schizophrenia due to their role in neural connectivity.
• Autoimmune Diseases: Abnormal CADM function can disrupt immune cell interactions, potentially contributing to autoimmune conditions.

Summary

Cell adhesion molecules (CADMs) are integral to maintaining cellular interactions and tissue structure. Their protein structure, including extracellular Ig-like domains, a transmembrane region, and a cytoplasmic tail, enables them to mediate crucial cellular functions. CADMs are involved in processes ranging from tumor suppression to neural development and immune response. Dysregulation of CADMs is associated with several diseases, particularly cancers and neurological disorders, making them significant both biologically and clinically. Understanding CADMs' mechanisms and interactions can provide insights into therapeutic targets for related pathologies.