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Phylogenetic Comparison of the Photoaffinity‐Labeled Benzodiazepine Receptor Subunits
Author(s) -
Hebebrand Johannes,
Friedl Waltraut,
Breidenbach Bernd,
Propping Peter
Publication year - 1987
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1987.tb05633.x
Subject(s) - lungfish , photoaffinity labeling , protein subunit , biology , phylogenetic tree , gel electrophoresis , phylogenetics , gene duplication , affinity label , biochemistry , benzodiazepine , evolutionary biology , biophysics , chemistry , genetics , receptor , gene , fish <actinopterygii> , fishery
The late evolutionary appearance of the benzodiazepine receptor (BZR) allows an experimental approach for evaluation of the qualitative development of its sub‐units. Photoaffinity labeling of brain membranes with [ 3 H]flunitrazepam followed by sodium dodecyl sulfate‐polyacrylamide gel electrophoresis and fluorography offers a suitable method for tracing the qualitative evolution of the BZR. A systematic comparison of the subunit patterns in fishes, amphibians, reptiles, birds, and mammals revealed that the subunit of 53K is phylogenetically the oldest photo‐affinity labeled subunit; whereas it is the only band present in the lungfish and most amphibians, additional bands are apparent in higher tetrapods. In fishes, the evolution of the BZR subunits leads to the loss of the 53K subunit. K D values are discussed in relation to specific subunit patterns. Possible explanations for the observed variation of the subunits are discussed, with special emphasis placed on the possible evolution by gene duplication and subsequent divergence.