ADCY5

ADCY5 Full Name

adenylate cyclase 5

ADCY5 Introduction

ADCY5 (adenylyl cyclase type 5) is a member of the adenylyl cyclase family of enzymes that catalyze the conversion of adenosine triphosphate (ATP) to cyclic adenosine monophosphate (cAMP), a critical second messenger involved in numerous cellular signaling pathways. The gene encoding ADCY5 is located on human chromosome 3q21.1 and produces a large transmembrane protein of approximately 1,260 amino acids with a molecular weight of around 140 kDa. Unlike some other adenylyl cyclase isoforms that are ubiquitously expressed, ADCY5 exhibits a more restricted tissue distribution, with highest expression levels in the striatum of the brain, as well as in the heart and other tissues. Mutations in the ADCY5 gene have been linked to several movement disorders, including familial dyskinesia and facial myokymia, highlighting its critical role in neurological function.

Figure 1. Strcuture of ADCY5.

Enzymatic Function and Catalytic Mechanism
ADCY5 catalyzes the formation of cAMP from ATP, a reaction that is tightly regulated by heterotrimeric G proteins downstream of G protein-coupled receptors (GPCRs). Upon activation of stimulatory GPCRs, the Gsα subunit dissociates from the G protein complex and binds directly to ADCY5 at the interface between the C1 and C2 domains, dramatically increasing its catalytic activity. Conversely, activation of inhibitory GPCRs leads to Giα binding, which suppresses ADCY5 activity. The enzyme also responds to intracellular calcium levels and protein kinase C (PKC) phosphorylation. The catalytic mechanism involves two metal ions (typically magnesium or manganese) that coordinate the phosphate groups of ATP, facilitating the nucleophilic attack of the 3'-hydroxyl group on the α-phosphate to form cAMP and pyrophosphate. This reaction is fundamental to cellular signaling, as cAMP activates downstream effectors such as protein kinase A (PKA) and exchange proteins activated by cAMP (Epac).

Tissue Distribution and Physiological Roles
ADCY5 exhibits a highly specific expression pattern that underlies its unique physiological functions. Within the central nervous system, ADCY5 is predominantly expressed in the striatum, a region critical for motor control, reward processing, and habit formation. It is enriched in medium spiny neurons, where it integrates dopamine and other neurotransmitter signals to regulate movement. In the heart, ADCY5 is expressed in cardiomyocytes and contributes to the regulation of cardiac contractility and heart rate in response to β-adrenergic stimulation. Unlike ADCY1, ADCY2, and ADCY3, which are more widely expressed, ADCY5 plays specialized roles in fine-tuning specific signaling pathways. Studies in knockout mice have demonstrated that ADCY5 is involved in motor coordination, anxiety-related behaviors, and metabolic regulation, including insulin secretion from pancreatic β-cells.

Alternate Names for ADCY5

ADCY5; adenylate cyclase 5; AC5; FDFM; adenylate cyclase type 5; adenylyl cyclase 5; adenylate cyclase type V; ATP pyrophosphate-lyase 5;