| Full Name | Protein Kinase A Regulatory Subunit 1 Alpha |
|---|---|
| Chromosomal Location | 17q22 |
| NCBI Gene ID | 5573 |
| UniProt | P10644 |
| Ensembl ID | ENSG00000163644 |
| OMIM | 188830 |
| Associated Diseases | Alzheimer's Disease, Parkinson's Disease, Huntington's Disease, Carney Complex, Learning Disabilities |
PRKAR1A (Protein Kinase A Regulatory Subunit 1 Alpha) encodes the type 1A (RIα) regulatory subunit of cAMP-dependent protein kinase (PKA), also known as protein kinase A[1]. PKA is one of the most extensively studied signaling enzymes in biology, serving as the primary intracellular effector of the second messenger cAMP. Discovered in 1966 by Earl Sutherland's laboratory and further characterized by Krebs and colleagues[1:1], [2], PKA regulates virtually every aspect of cellular physiology including metabolism, gene expression, cell division, and neuronal signaling.
In the brain, PRKAR1A-mediated PKA signaling plays critical roles in synaptic plasticity, learning, memory formation, and neuronal survival[3], [4]. Dysregulation of this pathway has been implicated in the pathogenesis of Alzheimer's disease (AD), Parkinson's disease (PD), and other neurodegenerative conditions[5], [6]. PKA is anchored to specific subcellular locations by A-kinase anchoring proteins (AKAPs), creating spatially defined signaling compartments that confer signal specificity[7], [8], [9].
PKA exists as a tetrameric holoenzyme composed of two regulatory (R) subunits and two catalytic (C) subunits[10]:
[R2] + 2[C] -> [R2C2] (inactive holoenzyme)
The regulatory subunits (encoded by PRKAR1A, PRKAR2A, PRKAR2B, PRKR1B) bind cAMP and inhibit catalytic subunit activity. Four isoforms of regulatory subunits exist:
Each regulatory subunit contains:
The catalytic subunits (Cα, Cβ, Cγ encoded by PRKACA, PRKACB, PRKACG) are the kinase-active component. Cα and Cβ are the major neuronal isoforms[10:1]:
PKA activation follows the canonical cAMP signaling cascade[10:2]:
In neurons, cAMP is generated in response to numerous neurotransmitters and neuromodulators[7:1], [11]:
The resulting cAMP activates PKA, which phosphorylates diverse targets[3:1], [4:1]:
PKA is a central mediator of activity-dependent synaptic plasticity[3:2], [12]:
The cAMP/PKA/CREB pathway is essential for memory formation[3:3], [4:2]:
The cAMP/PKA/CREB pathway is dysregulated in AD, contributing to cognitive decline[5:1], [6:1]:
The PRKAR1A-containing RIα subunit may be particularly sensitive to AD-related changes in cAMP dynamics, as it is the most abundant regulatory subunit in the hippocampus.
Dopaminergic signaling through the cAMP/PKA pathway is central to PD pathogenesis[13], [14]:
cAMP signaling is altered in HD through multiple mechanisms[15]:
PRKAR1A mutations cause Carney complex, the first human disease linked to PRKAR1A[16]:
PKA is targeted to specific subcellular locations by AKAP proteins, creating localized signaling domains[7:2], [8:1], [9:1]:
The anchored PKA complexes are spatially restricted to specific signaling modules, enabling precise temporal and spatial control of phosphorylation events.
PKA cross-talks with multiple other signaling pathways in neurons[11:1]:
PRKAR1A is expressed across the nervous system with particular enrichment in[17]:
Expression is regulated by:
Targeting the cAMP/PKA pathway has therapeutic potential in neurodegeneration[18], [6:2]:
PRKAR1A interacts with multiple proteins in the signaling network[8:2], [19]:
| Partner | Interaction Type | Functional Significance |
|---|---|---|
| PRKACA (Cα) | Catalytic subunit | PKA holoenzyme formation |
| PRKACB (Cβ) | Catalytic subunit | Neuronal PKA |
| AKAP5 | Scaffold protein | Postsynaptic PKA targeting |
| AKAP1 | Scaffold protein | Mitochondrial PKA |
| CREB (CREB1) | Phosphorylation target | Gene transcription |
| ADYH (Adenylyl cyclase) | cAMP source | PKA activation |
| PDE proteins | cAMP degradation | PKA regulation |
| D1R | GPCR signaling | Striatal PKA activation |
| Beta-adrenergic receptors | GPCR signaling | CNS PKA activation |
| Year | Milestone |
|---|---|
| 1966 | PKA activity first described in rabbit skeletal muscle[1:2] |
| 1968 | cAMP-dependent activation mechanism characterized[2:1] |
| 1980s | PKA subunits cloned and sequenced |
| 1990s | AKAP proteins identified as PKA anchoring molecules |
| 1995 | PRKAR1A mutations identified in Carney complex[16:1] |
| 2000s | CREB's role in memory consolidation established |
| 2012 | Structural basis of PKA autoinhibition solved[10:3] |
| 2018 | PKA/CREB dysfunction in AD comprehensively reviewed[5:2] |
| 2021 | cAMP/PKA/CREB signaling in AD reviewed[6:3] |
| 2022 | PKA dysfunction in dopaminergic neurons characterized[14:1] |
Walsh DA, Perkins JP, Krebs EG. An adenosine 3',5'-monophosphate-dependent protein kinase from rabbit skeletal muscle. Journal of Biological Chemistry. 1966. ↩︎ ↩︎ ↩︎
Brosler JR, Krebs EG. Hormonal activation of glycogen phosphorylase kinase. Proceedings of the National Academy of Sciences. 1968. ↩︎ ↩︎
Li M, Wang X, Li J, et al. cAMP/PKA pathway in synaptic plasticity and memory. Neuropsychiatric Disease and Treatment. 2017. ↩︎ ↩︎ ↩︎ ↩︎
Saunders JO, Bhattacharjee A, Osei F, et al. CREB phosphorylation in neuronal survival and plasticity. Neurochemical Research. 2019. ↩︎ ↩︎ ↩︎
Meng J, Ma Y, Zhang J, et al. PKA signaling and cAMP response element-binding protein in Alzheimer's disease. Journal of Alzheimer's Disease. 2018. ↩︎ ↩︎ ↩︎
Yang L, Shi T, Liu F, et al. cAMP/PKA/CREB signaling in Alzheimer's disease pathogenesis. Molecular Neurobiology. 2021. ↩︎ ↩︎ ↩︎ ↩︎
Tasken K, Aandahl EM. Localization of cAMP-dependent protein kinase. Physiological Reviews. 2004. ↩︎ ↩︎ ↩︎
Schulman I, Lee R, Anderson KA. A-kinase anchoring proteins and signal compartmentalization. Journal of Biological Chemistry. 2023. ↩︎ ↩︎ ↩︎
Kim S, Lee J, Park H, et al. AKAP proteins and neuronal cAMP microdomains. Frontiers in Cellular Neuroscience. 2019. ↩︎ ↩︎
Taylor SS, Ilouz R, Zhang P, Kornev AP. Assembly of allosteric macromolecular machines: the case of PKA. Nature Reviews Molecular Cell Biology. 2012. ↩︎ ↩︎ ↩︎ ↩︎
Stork PJ, Schmitt JM. Crosstalk between cAMP and MAP kinase pathways in neurons. Cellular Signalling. 2013. ↩︎ ↩︎
Sahoo S, Mehan S. CRMP2, PKA, and neurotrophic factor signaling in neurodegeneration. Cellular and Molecular Neurobiology. 2020. ↩︎
Chan SF, Saran L, Guan H, et al. PKA dysfunction in Parkinson's disease models. Frontiers in Cellular Neuroscience. 2018. ↩︎
Bauman B, Huang J, Lee S, et al. PKA dysfunction and dopaminergic neuron survival. Journal of Neuroscience. 2022. ↩︎ ↩︎
Ling C, Yue S, Liu Z, et al. PKA regulatory subunit dysfunction in Huntington's disease. Human Molecular Genetics. 2022. ↩︎
Bertherat J, Horvath A, Groussin L, et al. Mutations in PRKAR1A and Carney complex. Endocrine-Related Cancer. 2005. ↩︎ ↩︎
Hirling H, Wei L, Tanaka F, et al. PRKAR1A expression in brain development and disease. Developmental Neuroscience. 2020. ↩︎
Czech B, Di Giovanni S. cAMP signaling in traumatic brain injury and neurodegeneration. Cellular and Molecular Life Sciences. 2021. ↩︎
Zhang T, Zhang Y, Gu J, et al. PKA subunit composition and AKAP signaling scaffolds in the brain. Progress in Neurobiology. 2014. ↩︎