Adipokinetic hormones: cell and molecular biology

O’Shea, Michael; Rayne, Richard C.

doi:10.1007/bf01928161

Cited by 78 publications

(35 citation statements)

References 38 publications

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“…In addition, also from S. gregaria and S. nitans, unprocessed AAPs can be isolated in the form of homo-or heterodimers. In both Schistocerca species this dimerization also has to precede the prohormone processing at the Gly-LysArg or Gly-Arg-Arg sequences (7).…”

Section: Organization Of the Akh I Ii And Iii Preprohormones-mentioning

confidence: 99%

Molecular Cloning of Three Distinct cDNAs, Each Encoding a Different Adipokinetic Hormone Precursor, of the Migratory Locust, Locusta migratoria

Bogerd

Kooiman

Pijnenburg

et al. 1995

Journal of Biological Chemistry

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Three distinct cDNAs encoding the preproadipokinetic hormones I, II, and III (prepro-AKH I, II, and III), respectively, of Locusta migratoria have been isolated and sequenced. The three L. migratoria AKH precursors have an overall architecture similar to that of other precursors of the AKH/red pigment-concentrating hormone (RPCH) family identified so far. The AKH I and II precursors of L. migratoria are highly homologous to the Schistocerca gregaria and Schistocerca nitans AKH precursors. Although the L. migratoria AKH III precursor appears to be the least homologous to the Manduca sexta, Drosophila melanogaster, and Carcinus maenas AKH/RPCH precursors, we favor the opinion that the L. migratoria AKH III precursor is evolutionary more related to the M. sexta, D. melanogaster, and C. maenas AKH/RPCH precursors than to the AKH I and II precursors of S. gregaria, S. nitans, or L. migratoria. In situ hybridization showed signals for the different AKH mRNAs to be co-localized in cell bodies of the glandular lobes of the corpora cardiaca. Northern blot analysis revealed the presence of single mRNA species encoding the AKH I precursor (ϳ570 bases), AKH II precursor (ϳ600 bases), and AKH III precursor (ϳ670 bases), respectively. Interestingly, flight activity increased steady-state levels of the AKH I and II mRNAs (ϳ2.0 times each) and the AKH III mRNA (ϳ4.2 times) in the corpora cardiaca.Three peptide hormones with hyperlipemic activity, the adipokinetic hormones I, II and III (AKH 1 I, II and III; see Table I) (1-3), are synthesized by the glandular neurosecretory cells of the corpora cardiaca (CC) of the migratory locust, Locusta migratoria. These peptides are members of a large family of structurally related but functionally diverse peptides (the AKH/RPCH family) (4). In the adult locust, the AKHs I and II are released into the hemolymph during flight and are involved in the mobilization of lipid and carbohydrate from the fat body to serve as energy substrates for the flight muscles (4 -7). Data on the release and functioning of AKH III are lacking so far. Isolation and characterization of CC peptides revealed that two other locust species, Schistocerca gregaria and Schistocerca nitans, each contain two AKHs that are mutually identical (1, 8), whereas Manduca sexta and Drosophila melanogaster each contain only one AKH (9, 10) (see Table I).Molecular biological studies have resulted in the characterization of the structure of the AKH/RPCH precursors (a signal peptide, AKH/RPCH, a Gly-(Lys/Arg)-Arg sequence, and an AKH/RPCH-associated peptide (AAP/RAP), in this order) of S. gregaria, S. nitans, M. sexta, D. melanogaster,.The biosynthesis of the AKHs in S. gregaria has been elucidated in detail by O'Shea and co-workers (13, 18 -21). The signal peptide is co-translationally removed from prepro-AKH, generating pro-AKH. Next, proteolytic processing, which is preceded by dimerization of two pro-AKHs (I/I, I/II, or II/II) via their single COOH-terminal Cys residues, gives rise to two AKHs (I and/or II) and one homo-or hete...

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Section: Organization Of the Akh I Ii And Iii Preprohormones-mentioning

confidence: 99%

Molecular Cloning of Three Distinct cDNAs, Each Encoding a Different Adipokinetic Hormone Precursor, of the Migratory Locust, Locusta migratoria

Bogerd

Kooiman

Pijnenburg

et al. 1995

Journal of Biological Chemistry

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“…The ligand of the GnRH receptor of Drosophila melanogaster and Bombyx mori has been identified as adipokinetic hormone (AKH) (12). AKH is an insect neurohormone that is synthesized in the corpora cardiaca (CC) (13), a neurohemal organ that is considered the functional equivalent of the vertebrate pituitary gland. AKH is involved in mobilizing energycontaining substances such as sugar and lipids from the fat body during flight and locomotion (14).…”

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confidence: 99%

Adipokinetic hormone signaling through the gonadotropin-releasing hormone receptor modulates egg-laying in Caenorhabditis elegans

Lindemans

Liu

Janssen

et al. 2009

Proc. Natl. Acad. Sci. U.S.A.

136

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In mammals, hypothalamic gonadotropin-releasing hormone (GnRH) is a neuropeptide that stimulates the release of gonadotropins from the anterior pituitary. The existence of a putative functional equivalent of this reproduction axis in protostomian invertebrates has been a matter of debate. In this study, the ligand for the GnRH receptor in the nematode Caenorhabditis elegans (Ce-GnRHR) was found using a bioinformatics approach. The peptide and its precursor are reminiscent of both insect adipokinetic hormones and GnRH-preprohormone precursors from tunicates and higher vertebrates. We cloned the AKH-GnRH-like preprohormone and the Ce-GnRHR and expressed the GPCR in HEK293T cells. The GnRHR was activated by the C. elegans AKH-GnRH-like peptide (EC50 ‫؍‬ 150 nM) and by Drosophila AKH and other nematode AKH-GnRHs that we found in EST databases. Analogous to both insect AKH receptor and vertebrate GnRH receptor signaling, Ce-AKH-GnRH activated its receptor through a G␣q protein with Ca 2؉ as a second messenger. Gene silencing of Ce-GnRHR, Ce-AKHGnRH, or both resulted in a delay in the egg-laying process, comparable to a delay in puberty in mammals lacking a normal dose of GnRH peptide or with a mutated GnRH precursor or receptor gene. The present data support the view that the AKH-GnRH signaling system probably arose very early in metazoan evolution and that its role in reproduction might have been developed before the divergence of protostomians and deuterostomians.C. elegans ͉ G protein-coupled receptor ͉ molecular evolution ͉ neuropeptide ͉ neuroendocrinology

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“…A related peptide called AKH II (Glp-Leu-Asn-Phe-Ser-Thr-GlyTi-pNH,; Siegert et al, 1985) is also synthesized by the same neurosecretory cells, being processed from a different prohormone (Fischer-Lougheed et al, 1993). The glandular lobes of the locust corpora cardiucu comprise a homogeneous population of AKH-producing cells and as such represent a favourable system for direct studies of prohormone processing in an intact neuroendocrine gland (O'Shea and Rayne, 1992). Moreover, proAKH I is only 41 amino acids in length and possesses only a single dibasic processing site (Schulz-Aellen et al, 1989;Hekimi et al, 1989;O'Shea et al, 1990).…”

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Structural requirements for processing of pro‐adipokinetic hormone I

Rayne

O’Shea

1993

European Journal of Biochemistry

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We found that a seven‐residue sequence in pro‐adipokinetic hormone I (proAKH I) which precedes the endopeptidase cleavage site is predicted to form an Ω loop. Molecular modelling experiments indicated that a stable Ω loop may form at this site, and suggested that loop stability may depend on the C‐terminal loop residue, Lys12. The importance of this residue in proAKH I processing was confirmed by the observation that replacement of Lys12 by thialysine, a Lys analog with an altered side chain, prevented processing in vivo. In addition we showed by molecular modelling that this side‐chain alteration may prevent formation of an Ω loop. Together, these approaches lead us to propose that an Ω loop may serve as a recognition motif in proAKH I processing.

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Adipokinetic hormones: cell and molecular biology

Cited by 78 publications

References 38 publications

Molecular Cloning of Three Distinct cDNAs, Each Encoding a Different Adipokinetic Hormone Precursor, of the Migratory Locust, Locusta migratoria

Molecular Cloning of Three Distinct cDNAs, Each Encoding a Different Adipokinetic Hormone Precursor, of the Migratory Locust, Locusta migratoria

Adipokinetic hormone signaling through the gonadotropin-releasing hormone receptor modulates egg-laying in Caenorhabditis elegans

Structural requirements for processing of pro‐adipokinetic hormone I

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