Calmodulin 1

Calmodulin 1

Calmodulin 1 (CaM1) is a highly conserved, calcium-binding messenger protein expressed in all eukaryotic cells. It is a member of the calmodulin family, which plays a pivotal role in calcium signaling by interacting with various target proteins and enzymes. Calmodulin 1 is encoded by the CALM1 gene in humans.

Structure

Calmodulin 1 is a small, acidic protein composed of 148 amino acids. It has a dumbbell-shaped structure with two globular domains connected by a flexible linker. Each domain contains two EF-hand motifs, which are helix-loop-helix structures capable of binding calcium ions. Upon binding calcium, calmodulin undergoes a conformational change that enables it to interact with a wide range of target proteins.

Function

Calmodulin 1 functions as an intracellular calcium sensor and signal transducer. It regulates various cellular processes by modulating the activity of its target proteins in response to changes in intracellular calcium levels. Some of the key processes regulated by calmodulin include:

• Muscle contraction
• Cell division
• Cell motility
• Intracellular transport
• Gene expression

Calmodulin 1 interacts with and regulates the activity of numerous enzymes, ion channels, and other proteins, including:

• Calcium/calmodulin-dependent protein kinases (CaMKs)
• Phosphatases such as calcineurin
• Adenylyl cyclases
• Ion channels like the ryanodine receptor and L-type calcium channel

Clinical Significance

Mutations in the CALM1 gene can lead to various disorders, particularly those affecting the heart. Calmodulinopathies, a group of rare genetic conditions, are associated with mutations in calmodulin genes, including CALM1. These conditions can cause severe cardiac arrhythmias, such as:

• Long QT syndrome
• Catecholaminergic polymorphic ventricular tachycardia (CPVT)

Research is ongoing to better understand the role of calmodulin 1 in these and other diseases, as well as its potential as a therapeutic target.

Also see

• Calmodulin
• Calcium signaling
• EF-hand motif
• Calcium/calmodulin-dependent protein kinase
• Long QT syndrome