Sayeed Ur Rehman, Abdul Rouf Banday, Mohammad Tabish
Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University, Aligarh, U.P. 202002, India.
Cyclic AMP-dependent protein kinase A (PKA) is an essential enzyme involved in the signalling pathway of the second messenger cAMP. Through phosphorylation of target proteins, PKA controls many biological events in the cell including regulation of lipid and glucose metabolism, gene transcription and ion transport. PKA holoenzyme consists of two catalytic and two regulatory subunits. There are multiple isoforms of regulatory subunits. The prkar1b gene encodes regulatory type 1 beta (R1β) subunit of PKA. It is differentially expressed in various tissue types in different organism and under different disease states. This gene is important for neurological functions and has been implicated in synaptic plasticity, memory and learning and systemic lupus erythematosus (SLE). Here we report that mouse R1β gene produces three alternative splice variants that have different N-terminal protein structure designated mR1β1, mR1β2 and mR1β3. These splice variants were identified using combination of different bioinformatics tool and databases. Further, molecular biology techniques involving RT-PCR, semi-nested PCR and sequencing were used to confirm the findings. Except mR1β3, which was not detected by RT-PCR in brain and muscle tissue of 3 day old mice, all three spliced isoforms were found to be ubiquitously expressed in tissues and postnatal developmental stages examined. Our results suggest that the presence of different isoforms may play specific roles as individually or in different holoenzyme complexes and may have unique docking interaction with A kinase Anchoring proteins (AKAPs). Read More …