STRN - Striatin | Elisa - Clia - Antibody - Protein

Background

Striatin (STRN) is a protein encoded by the STRN gene located on chromosome 2p22-p21. It is a multifunctional scaffolding protein involved in various cellular processes, including signal transduction, cytoskeletal organization, and cellular communication. Striatin is predominantly expressed in neuronal tissues, particularly in the brain's striatum, but it is also found in other tissues such as the heart and muscle. It plays a key role in the regulation of protein phosphatase 2A (PP2A) activity, a major serine/threonine phosphatase involved in numerous cellular functions, including cell growth, division, and apoptosis.

Striatin belongs to the STRIPAK (striatin-interacting phosphatase and kinase) complex, which integrates signaling pathways that control cytoskeletal dynamics, vesicular trafficking, and other essential cellular activities. Its involvement in the regulation of PP2A and association with various signaling proteins underscores its importance in maintaining cellular homeostasis and function.

Protein Structure

The striatin protein is characterized by several distinct domains that facilitate its diverse functions:

• Calmodulin-Binding Domain: Allows interaction with calmodulin, a calcium-binding messenger protein that regulates various cellular processes in response to calcium levels.
• WD40 Repeats: A series of repeating sequences involved in protein-protein interactions, contributing to the scaffolding functions of striatin.
• Coiled-Coil Domain: Facilitates the formation of protein complexes by enabling interactions with other coiled-coil domain-containing proteins.
• Leucine-Rich Repeats (LRR): Involved in protein-protein interactions, further aiding in the assembly of multi-protein complexes.

Classification and Subtypes

Striatin is a member of the striatin family of proteins, which includes striatin 1, striatin 2, and striatin 3 (SG2NA). These proteins share structural similarities and functional roles in cellular signaling and scaffolding.

Function and Biological Significance

Striatin's primary functions and biological significance include:

• Signal Transduction: Acts as a scaffold for the assembly of signaling complexes, particularly those involving PP2A, which is crucial for dephosphorylation events in various signaling pathways.
• Cytoskeletal Organization: Regulates the dynamics of the cytoskeleton, influencing cell shape, motility, and intracellular transport.
• Cell-Cell Communication: In neurons, striatin is involved in synaptic signaling and plasticity, essential for learning and memory.
• Regulation of PP2A Activity: Striatin modulates the activity of PP2A, affecting processes such as cell cycle progression, apoptosis, and response to DNA damage.

Clinical Issues

Dysregulation of striatin and its associated pathways has been implicated in several diseases:

• Neurological Disorders: Abnormal striatin expression or function is linked to neurological conditions such as Huntington's disease and certain types of epilepsy.
• Cancer: Changes in striatin expression and PP2A regulation are associated with tumorigenesis, highlighting its potential role in cancer progression.
• Cardiovascular Diseases: Striatin has been implicated in heart disease, where its role in calcium signaling and PP2A regulation affects cardiac function.

Summary

Striatin (STRN) is a multifaceted scaffolding protein involved in critical cellular processes, particularly signal transduction, cytoskeletal organization, and cellular communication. It regulates protein phosphatase 2A (PP2A) activity, impacting cell growth, division, and apoptosis. Striatin's diverse roles and interactions underscore its importance in maintaining cellular homeostasis. Dysregulation of striatin is linked to neurological disorders, cancer, and cardiovascular diseases, making it a significant protein of interest in biomedical research. Understanding the mechanisms by which striatin functions and its role in disease can inform therapeutic strategies targeting these pathways.