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Role of the fourth intracellular loop of D1‐like dopaminergic receptors in conferring subtype‐specific signaling properties
Author(s) -
Tumova Katerina,
Zhang Dongling,
Tiberi Mario
Publication year - 2004
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/j.febslet.2004.09.059
Subject(s) - receptor , dopamine receptor , dopaminergic , intracellular , microbiology and biotechnology , dopamine , biology , endocrinology , biochemistry
We investigate whether the fourth intracellular loop (IL4) of D1 and D5 dopaminergic receptors (D1R, D5R) confers D1‐like subtype‐specific signaling properties. Using chimeric receptors (D1R‐IL4B and D5R‐IL4A), we show that swapping of IL4 leads to a switch in dopamine affinity and constitutive activity of D1R and D5R. Dopamine potency was reduced for both chimeras in comparison with wild‐type receptors. Moreover, dopamine‐mediated maximal activation was drastically increased in cells expressing D1R‐IL4B when compared with those harboring D5R‐IL4A or wild‐type receptors. In conclusion, IL4 plays a pivotal role in imparting subtype‐specific ligand binding and activation properties to highly homologous seven‐transmembrane receptors.