GNB5

Heterotrimeric guanine nucleotide-binding proteins (G proteins), which integrate signals between receptors and effector proteins, are composed of an alpha, a beta, and a gamma subunit. These subunits are encoded by families of related genes. This gene encodes a beta subunit. Beta subunits are important regulators of alpha subunits, as well as of certain signal transduction receptors and effectors. Alternatively spliced transcript variants encoding different isoforms exist.

Full Name

G protein subunit beta 5

Function

Enhances GTPase-activating protein (GAP) activity of regulator of G protein signaling (RGS) proteins, hence involved in the termination of the signaling initiated by the G protein coupled receptors (GPCRs) by accelerating the GTP hydrolysis on the G-alpha subunits, thereby promoting their inactivation (Probable). Increases RGS9 GTPase-activating protein (GAP) activity, hence contributes to the deactivation of G protein signaling initiated by D2 dopamine receptors (PubMed:27677260).

May play an important role in neuronal signaling, including in the parasympathetic, but not sympathetic, control of heart rate (By similarity).

Biological Process

Dopamine receptor signaling pathway Source: UniProtKB
G protein-coupled receptor signaling pathway Source: GO_Central
Negative regulation of voltage-gated calcium channel activity Source: UniProtKB
Positive regulation of GTPase activity Source: UniProtKB
Signal transduction Source: UniProtKB

Cellular Location

Membrane

Involvement in disease

Intellectual developmental disorder with cardiac arrhythmia (IDDCA):
An autosomal recessive multisystem disorder characterized by delayed psychomotor development, severe intellectual disability with poor or absent speech, and bradycardia and/or cardiac sinus arrhythmias. Additional features include visual abnormalities, seizures, hypotonia, and gastric reflux.
Language delay and attention deficit-hyperactivity disorder/cognitive impairment with or without cardiac arrhythmia (LADCI):
An autosomal recessive neurodevelopmental disorder characterized by speech impairment and variable expressivity of attention deficit hyperactivity disorder. Some patients manifest developmental and motor delay, hypotonia, and sinus-node dysfunction.