What is a type of protein that forms ion channels activated by changes in electrical membrane potential?

Voltage-gated channels are specialized proteins that open or close in response to changes in the membrane potential of a cell. When the electrical charge across the membrane reaches a specific threshold, these channels undergo a conformational change that allows ions to flow through. This process is crucial in the generation and propagation of action potentials in neuron communication and muscle contraction. For example, during an action potential, voltage-gated sodium channels open rapidly in response to depolarization, allowing sodium ions to enter the cell, which contributes to the rising phase of the action potential.

Other types of ion channels, such as ligand-gated channels, are activated by the binding of chemical messengers rather than changes in voltage. Mechanosensitive channels respond to mechanical forces, such as stretch or pressure, instead of electrical changes. Leak channels provide a passive pathway for ions to flow, maintaining resting membrane potential but do not respond to voltage changes. Thus, voltage-gated channels are distinct in their dependence on the membrane potential for activation, making them essential in many physiological processes.