Molecular and cellular specificity of post-translational aminoacyl isomerization in the crustacean hyperglycaemic hormone family.
D-aminoacyl residues have been detected in various animal peptides from several taxa, especially vertebrates and arthropods. This unusual polymorphism was shown to occur in isoforms of the crustacean hyperglycaemic hormone (CHH) of the American lobster because a D-phenylalanyl residue was found in position 3 of the sequence (CHH and D-Phe3 CHH). In the present study, we report the detailed strategy used to characterize, in the lobster neuroendocrine system, isomers of another member of the CHH family, vitellogenesis inhibiting hormone (VIH). We have demonstrated that the fourth residue is either an L- or a D- tryptophanyl residue (VIH and D-Trp4 VIH). Furthermore, use of antisera specifically recognizing the epimers of CHH and VIH reveals that aminoacyl isomerization occurs in specialized cells of the X organ-sinus gland neurosecretory system and that the D-forms of the two neuropeptides are not only present in the same cells, but, importantly, also are co-packaged within the same secretory vesicles.
Ollivaux
Céline
C
Université Pierre et Marie Curie-Paris 06, UMR 7150 Mer et Santé, Equipe Physiologie Comparée des Erythrocytes, Station Biologique de Roscoff, France. celine.ollivaux@upmc.fr
Gallois
Dominique
D
Amiche
Mohamed
M
Boscaméric
Maryse
M
Soyez
Daniel
D
D049148:Aminoacylation; D000818:Animals; D060829:Arthropod Proteins; D002352:Carrier Proteins / Q000378:metabolism; D007447:Invertebrate Hormones / Q000378:metabolism; D008121:Nephropidae / Q000378:metabolism*; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D009490:Neurosecretory Systems / Q000378:metabolism; D020033:Protein Isoforms / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D013237:Stereoisomerism
D060829:Arthropod Proteins; D002352:Carrier Proteins; D007447:Invertebrate Hormones; D009419:Nerve Tissue Proteins; D020033:Protein Isoforms; C015947:hyperglycemic hormone, crustacean; C073189:vitellogenesis inhibiting hormone