PRKAR1A

cAMP is a signaling molecule important for a variety of cellular functions. cAMP exerts its effects by activating the cAMP-dependent protein kinase, which transduces the signal through phosphorylation of different target proteins. The inactive kinase holoenzyme is a tetramer composed of two regulatory and two catalytic subunits. cAMP causes the dissociation of the inactive holoenzyme into a dimer of regulatory subunits bound to four cAMP and two free monomeric catalytic subunits. Four different regulatory subunits and three catalytic subunits have been identified in humans. This gene encodes one of the regulatory subunits. This protein was found to be a tissue-specific extinguisher that down-regulates the expression of seven liver genes in hepatoma x fibroblast hybrids. Mutations in this gene cause Carney complex (CNC). This gene can fuse to the RET protooncogene by gene rearrangement and form the thyroid tumor-specific chimeric oncogene known as PTC2. A nonconventional nuclear localization sequence (NLS) has been found for this protein which suggests a role in DNA replication via the protein serving as a nuclear transport protein for the second subunit of the Replication Factor C (RFC40). Several alternatively spliced transcript variants encoding two different isoforms have been observed.

Full Name

protein kinase cAMP-dependent type I regulatory subunit alpha

Function

Regulatory subunit of the cAMP-dependent protein kinases involved in cAMP signaling in cells.

Biological Process

Cardiac muscle cell proliferationIEA:Ensembl
Intracellular signal transductionManual Assertion Based On ExperimentTAS:ProtInc
Mesoderm formationIEA:Ensembl
Negative regulation of activated T cell proliferationManual Assertion Based On ExperimentIMP:UniProtKB
Negative regulation of cAMP-dependent protein kinase activityManual Assertion Based On ExperimentIDA:BHF-UCL
Negative regulation of gene expressionManual Assertion Based On ExperimentIMP:ARUK-UCL
Regulation of transcription by RNA polymerase IIManual Assertion Based On ExperimentTAS:ProtInc
Sarcomere organizationIEA:Ensembl

Cellular Location

Cell membrane

Involvement in disease

Carney complex 1 (CNC1):
CNC is a multiple neoplasia syndrome characterized by spotty skin pigmentation, cardiac and other myxomas, endocrine tumors, and psammomatous melanotic schwannomas.
Intracardiac myxoma (INTMYX):
Inheritance is autosomal recessive.
Primary pigmented nodular adrenocortical disease 1 (PPNAD1):
A rare bilateral adrenal defect causing ACTH-independent Cushing syndrome. Macroscopic appearance of the adrenals is characteristic with small pigmented micronodules observed in the cortex. Clinical manifestations of Cushing syndrome include facial and truncal obesity, abdominal striae, muscular weakness, osteoporosis, arterial hypertension, diabetes. PPNAD1 is most often diagnosed in patients with Carney complex, a multiple neoplasia syndrome. However it can also be observed in patients without other manifestations.
Acrodysostosis 1, with or without hormone resistance (ACRDYS1):
A form of skeletal dysplasia characterized by short stature, severe brachydactyly, facial dysostosis, and nasal hypoplasia. Affected individuals often have advanced bone age and obesity. Laboratory studies show resistance to multiple hormones, including parathyroid, thyrotropin, calcitonin, growth hormone-releasing hormone, and gonadotropin. However, not all patients show endocrine abnormalities.

PTM

The pseudophosphorylation site binds to the substrate-binding region of the catalytic chain, resulting in the inhibition of its activity.