Posttranslational isomerization of a neuropeptide in crustacean neurosecretory cells studied by ultrastructural immunocytochemistry
| Autor: | Dominique Gallois, Marie-Jeanne Brisorgueil, Marie Conrath, Daniel Soyez, Philippe Mailly |
|---|---|
| Přispěvatelé: | Neurobiologie des signaux intercellulaires (NSI), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Marie, Jean-Luc |
| Jazyk: | angličtina |
| Rok vydání: | 2003 |
| Předmět: |
Male
Histology Invertebrate Hormones [SDV.NEU.NB]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]/Neurobiology Molecular Sequence Data Nerve Tissue Proteins Astacoidea Astacus leptodactylus Arthropod Proteins Pathology and Forensic Medicine Exocrine Glands Isomerism Axon terminal medicine Animals Amino Acid Sequence Axon Secretory pathway biology Neuropeptides Granule (cell biology) [SDV.NEU.NB] Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]/Neurobiology Cell Biology General Medicine Immunogold labelling Orconectes limosus biology.organism_classification Immunohistochemistry Neurosecretory Systems medicine.anatomical_structure Biochemistry Ultrastructure Female Protein Processing Post-Translational |
| Zdroj: | Eur J Cell Biol. Eur J Cell Biol., 2003, 82 (8), pp.431-440 |
| Popis: | Summary Isomerization of the third amino acid residue (a phenylalanine) of crustacean hyperglycemic hormone (CHH) has been previously reported to occur as a late step of hormone precursor maturation in a few neurosecretory cells in the X-organ-sinus gland complex of the crayfish Orconectes limosus . In the present report, using conformation-specific antisera combined with immunogold labeling, we have studied, at the ultrastructural level, the distribution of L- and D-CHH immunoreactivity in CHH-secreting cells of the crayfish Astacus leptodactylus . Two CHH-secreting cell populations were observed, the first one (L-cells), the most numerous, exhibited only labeling for L-CHH. In the second one (D-cells), four secretory granule populations were distinguished according to their labeling: unlabeled, either L- or D- exclusively or both L- and D-granules. Labeling quantification by image analysis in D-cells showed a marked increase in D-labeling from the cell body to the axon terminal. However some L- and mixed granules remain in axon terminals. Our results demonstrate that Phe 3 isomerization of CHH occurs within the secretory granules of specialized neurosecretory cells and progresses as the granules migrate along the axonal tract. The observation that not all the CHH synthesized is isomerized, and the great variability in the proportion of L- and D-immunoreactivity in granules in every cell region may suggest an heterogeneous distribution of the putative enzyme involved in Phe 3 isomerization, a peptide isomerase, within the secretory pathway. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|