Description
PRKAR1A, also known as PRKAR1 and PKR1, is one of the regulatory subunits of cAMP-dependent protein kinase A (PKA). PKA can be activated by cAMP. cAMP is a signaling molecule important for a variety of cellular functions. cAMP exerts its effects by activating PKA, which transduces the signal throughphosphorylation of different target proteins. The inactive holoenzyme of PKA 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 of PKA have been identified in humans. PRKAR1A was found to be a tissue-specific extinguisher that down-regulates the expression of seven liver genes in hepatoma x fibroblast hybrids Three alternatively spliced transcript variants encoding the same protein have been observed