Calcium homeostasis modulator 1 (CALHM1) is a pore-forming subunit of a

voltage-gated ion channel Voltage-gated ion channels are a class of transmembrane proteins that form ion channels that are activated by changes in the electrical membrane potential near the channel. The membrane potential alters the conformation of the channel proteins, ...

and a voltage-gated ATP channel that in humans is encoded by the ''CALHM1''

gene In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a ba ...

Function

Central nervous system

CALHM1 was identified by a tissue-specific gene expression profiling approach that screened for genes located on susceptibility loci for late-onset

Alzheimer's disease Alzheimer's disease (AD) is a neurodegeneration, neurodegenerative disease that usually starts slowly and progressively worsens. It is the cause of 60–70% of cases of dementia. The most common early symptom is difficulty in short-term me ...

(AD) and that are preferentially expressed in the hippocampus, a brain region affected early in AD. CALHM1 is a plasma membrane calcium-permeable

ion channel Ion channels are pore-forming membrane proteins that allow ions to pass through the channel pore. Their functions include establishing a resting membrane potential, shaping action potentials and other electrical signals by gating the flow of io ...

regulated by voltage and extracellular calcium levels. The exact function of CALHM1 in the brain is not completely understood, but studies have shown that CALHM1 controls neuronal intracellular calcium homeostasis and signaling, as well as calcium-dependent neuronal excitability and memory in mouse models. Recent data have also shown that CALHM1 might facilitate the

proteolytic Proteolysis is the breakdown of proteins into smaller polypeptides or amino acids. Uncatalysed, the hydrolysis of peptide bonds is extremely slow, taking hundreds of years. Proteolysis is typically catalysed by cellular enzymes called proteases, ...

degradation of the cerebral

amyloid beta Amyloid beta (Aβ or Abeta) denotes peptides of 36–43 amino acids that are the main component of the amyloid plaques found in the brains of people with Alzheimer's disease. The peptides derive from the amyloid precursor protein (APP), which is ...

peptide, a culprit in AD

pathogenesis Pathogenesis is the process by which a disease or disorder develops. It can include factors which contribute not only to the onset of the disease or disorder, but also to its progression and maintenance. The word comes from Greek πάθος ''pat ...

Peripheral taste system

CALHM1 is expressed in

taste bud Taste buds contain the taste receptor cells, which are also known as gustatory cells. The taste receptors are located around the small structures known as lingual papillae, papillae found on the upper surface of the tongue, soft palate, upper e ...

cells where it controls

purinergic receptor Purinergic receptors, also known as purinoceptors, are a family of plasma membrane molecules that are found in almost all mammalian tissues. Within the field of purinergic signalling, these receptors have been implicated in learning and memory, lo ...

-mediated taste transduction in the

gustatory system The gustatory system or sense of taste is the sensory system that is partially responsible for the perception of taste (flavor). Taste is the perception produced or stimulated when a substance in the mouth reacts chemically with taste receptor ...

Function

Central nervous system

Peripheral taste system

See also

References

External links

Further reading