Protein Kinase A regulatory subunit I beta Antibody

Background:

The second messenger cyclic AMP (cAMP) mediates diverse cellularresponses to external signals such as proliferation, ion transport, regulationof metabolism and gene transcription by activation of the cAMP-dependentprotein kinase (cAPK or PKA). Activation of PKA occurs when cAMP binds tothe two regulatory subunits of the tetrameric PKA holoenzyme resulting inrelease of active catalytic subunits. Three catalytic (C) subunits have beenidentified, designated Cα, Cβ and Cγ, that each represent specific geneproducts. Cα and Cβ are closely related (93% amino acid sequence similari-ty), whereas Cγ displays 83% and 79% similarity to Cα and Cβ, respectively.Activation of transcription upon elevation of cAMP levels results fromtranslocation of PKA to the nucleus where it phosphorylates the transcrip-tion factor cAMP response element binding protein (CREB) on serine 133which in turn leads to TFIIB binding to TATA-box-binding protein TBP1, thuslinking phospho-CREB to the pol II transcription initiation complex.