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Preparation of Synaptic Plasma Membrane and Postsynaptic Density Proteins Using a Discontinuous Sucrose Gradient
Published on: September 3, 2014
Structure, processing and evolution of the neurohypophysial hormone-neurophysin precursors
Biochimie
|September 1, 1988
Summary
Neurohypophysial hormones like oxytocin and vasopressin evolve uniquely across marsupials and other vertebrates. Their precursor proteins and processing pathways show significant evolutionary divergence, impacting hormone diversity.
Area of Science:
- Neuroendocrinology
- Evolutionary Biology
- Molecular Biology
Background:
- Neurohypophysial hormones (oxytocin-like, vasopressin-like) and neurophysins derive from common precursors.
- Vertebrates typically possess two neurohormones and two neurophysins, but marsupial evolution presents unique variations.
- These precursors are processed during axonal transport from the hypothalamus to the neurohypophysis.
Purpose of the Study:
- To investigate the evolutionary divergence of neurohypophysial hormone precursors and their processing pathways.
- To compare hormone and neurophysin repertoires across different vertebrate lineages, particularly marsupials.
- To elucidate the mechanisms and evolutionary stability of precursor processing.
Main Methods:
- Comparative analysis of neurohypophysial hormone and neurophysin sequences across species.
- Identification and characterization of pressor peptides in marsupial glands.
- In vitro processing studies of intermediate precursors using enzymatic methods.
Main Results:
- Marsupials exhibit unique vasopressin gene duplication and varied oxytocin presence (e.g., lysipressin, phenylpressin, mesotocin).
- Neurophysin domains show evolutionary stability, particularly the central parts encoded by central exons.
- Mammalian vasopressin precursor processing involves two distinct enzymatic cleavages, while non-mammalian tetrapods may utilize a single cleavage step.
Conclusions:
- The evolution of neurohypophysial hormone precursors is marked by lineage-specific gene duplication and varied hormone retention.
- Recurrent gene conversion events appear to link the evolutionary trajectories of precursor lineages.
- Differential processing mechanisms contribute to the diversity of neurohypophysial hormone function across vertebrates.
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