**JPH2**
**Definition**
JPH2 (Junctophilin-2) is a protein encoded by the JPH2 gene in humans, essential for the structural integrity and function of cardiac muscle cells. It plays a critical role in the formation of junctional membrane complexes that facilitate communication between the plasma membrane and the sarcoplasmic reticulum.
**Article**
## Overview
Junctophilin-2 (JPH2) is a member of the junctophilin family of proteins, which are involved in maintaining close contact between the plasma membrane and intracellular calcium stores. JPH2 is predominantly expressed in cardiac muscle and is vital for excitation-contraction coupling, the process by which electrical signals trigger muscle contraction.
## Structure and Function
JPH2 contains membrane occupation and recognition nexus (MORN) motifs that anchor it to the plasma membrane, while its C-terminal region interacts with the sarcoplasmic reticulum. This positioning allows JPH2 to form junctional membrane complexes that enable efficient calcium signaling necessary for heart muscle contraction.
## Clinical Significance
Mutations or altered expression of JPH2 have been linked to various cardiac diseases, including hypertrophic cardiomyopathy and heart failure. Research into JPH2 function and regulation continues to provide insights into cardiac physiology and potential therapeutic targets.
**Meta Description**
JPH2 is a cardiac protein crucial for excitation-contraction coupling by linking the plasma membrane and sarcoplasmic reticulum. It is significant in maintaining heart muscle function and is associated with cardiac diseases.