HCN4
Encyclopedia
Potassium/sodium hyperpolarization-activated cyclic nucleotide-gated channel 4 is a protein
that in humans is encoded by the HCN4 gene
.
There are four HCN channel
s. HCN4 is prominently expressed in the pace maker region of the mammalian heart
. Some humans with bradycardia
and Sick sinus syndrome
have been shown to have mutations in their HCN4 gene. The role of HCN channels in autonomic
control of heart rate is currently a matter of ongoing investigation.
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
that in humans is encoded by the HCN4 gene
Gene
A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...
.
There are four HCN channel
HCN channel
Hyperpolarization-activated cyclic nucleotide-gated channels are proteins that serve as ion channels across the plasma membrane of heart and brain cells. HCN channels are sometimes referred to as “pacemaker channels” because they help to generate rhythmic activity within groups of heart and brain...
s. HCN4 is prominently expressed in the pace maker region of the mammalian heart
Heart
The heart is a myogenic muscular organ found in all animals with a circulatory system , that is responsible for pumping blood throughout the blood vessels by repeated, rhythmic contractions...
. Some humans with bradycardia
Bradycardia
Bradycardia , in the context of adult medicine, is the resting heart rate of under 60 beats per minute, though it is seldom symptomatic until the rate drops below 50 beat/min. It may cause cardiac arrest in some patients, because those with bradycardia may not be pumping enough oxygen to their heart...
and Sick sinus syndrome
Sick sinus syndrome
Sick sinus syndrome, also called sinus node dysfunction, is a group of abnormal heart rhythms presumably caused by a malfunction of the sinus node, the heart's primary pacemaker...
have been shown to have mutations in their HCN4 gene. The role of HCN channels in autonomic
Autonomic nervous system
The autonomic nervous system is the part of the peripheral nervous system that acts as a control system functioning largely below the level of consciousness, and controls visceral functions. The ANS affects heart rate, digestion, respiration rate, salivation, perspiration, diameter of the pupils,...
control of heart rate is currently a matter of ongoing investigation.