cDNA-Derived Amino Acid Sequence from Rat Brain A{sub}(2a)R Possesses Conserved Motifs PMNYM of TM 5 Domain, Which May Be Involved in Dimerization of A{sub}(2a)R

摘要

The human adenosine A{sub}(2a) receptor (A{sub}(2a)R) belongs to the family of G-protein coupled receptors (GPCRs), characterized by seven transmembrane (TM) helices. TMs are involved in various cellular processes including dimerization-mediated recognition of ligand. TM5 has been suggested to self associate and may be involved in the dimerization of A{sub}(2a)R. However the role of dimerization and the motifs involved in dimerization of TM 5 have not been revealed. To study the folding and assembly of A{sub}(2a)R, the cDNA of the adenosine A{sub}(2a)R from rat brain was isolated and sequenced (DQ098650). The computational analysis (gi|70727927|gb|AAZ07991.1|) showed that the protein of 42 amino acid residues aligned in TM 5 domain region of AA2AR_RAT (P30543). PROSITE search illustrated that the motif PMNYM was conserved in A{sub}(2a)R and the motif PMSYM was present in A{sub}(2b)R respectively. The minimal dimerization motif in the TM 5 domain of the rat A{sub}(2a) receptor sequence DQ098650 has found to be the motif PXXXM/Y.