Crustacean hyperglycaemic hormone (CHH)-like peptides and CHH-precursor-related peptides from pericardial organ neurosecretory cells in the shore crab, Carcinus maenas, are putatively spliced and modified products of multiple genes
Dircksen, H.; Bocking, D.; Heyn, U.; Mandel, C.; Chung, J.S.; Baggerman, G.; Verhaert, P.; Daufeldt, S.; Plösch, T.; Jaros, P.P.; Waelkens, E.; Keller, R.; Webster, S.G. (2001). Crustacean hyperglycaemic hormone (CHH)-like peptides and CHH-precursor-related peptides from pericardial organ neurosecretory cells in the shore crab, Carcinus maenas, are putatively spliced and modified products of multiple genes. Biochem. J. 356(1): 159-170. https://dx.doi.org/10.1042/0264-6021:3560159 In: Biochemical journal. Biochemical Society: London. ISSN 0264-6021; e-ISSN 1470-8728, more |  |
| Author keywords | alternative splicing; immunocytochemistry; neuropeptide; neurosecretion |
| Authors | | Top | - Dircksen, H.
- Bocking, D.
- Heyn, U.
- Mandel, C.
- Chung, J.S.
| - Baggerman, G.
- Verhaert, P.
- Daufeldt, S.
- Plösch, T.
| - Jaros, P.P.
- Waelkens, E., more
- Keller, R.
- Webster, S.G.
|
| Abstract | About 24 intrinsic neurosecretory neurons within the pericardial organs (POs) of the crab Carcinus maenas produce a novel crustacean hyperglycaemic hormone (CHH)-like peptide (PO-CHH) and two CHH-precursor-related peptides (PO-CPRP I and II) as identified immunochemically and by peptide chemistry. Edman sequencing and MS revealed PO-CHH as a 73 amino acid peptide (8630Da) with a free C-terminus. PO-CHH and sinus gland CHH (SG-CHH) share an identical N-terminal sequence, positions 1–40, but the remaining sequence, positions 41–73 or 41–72, differs considerably. PO-CHH may have different precursors, as cDNA cloning of PO-derived mRNAs has revealed several similar forms, one exactly encoding the peptide. All PO-CHH cDNAs contain a nucleotide stretch coding for the SG-CHH41–76 sequence in the 3′-untranslated region (UTR). Cloning of crab testis genomic DNA revealed at least four CHH genes, the structure of which suggest that PO-CHH and SG-CHH arise by alternative splicing of precursors and possibly post-transcriptional modification of PO-CHH. The genes encode four exons, separated by three variable introns, encoding part of a signal peptide (exon I), the remaining signal peptide residues, a CPRP, the PO-CHH1–40/SG-CHH1–40 sequences (exon II), the remaining PO-CHH residues (exon III) and the remaining SG-CHH residues and a 3′-UTR (exon IV). Precursor and gene structures are more closely related to those encoding related insect ion-transport peptides than to penaeid shrimp CHH genes. PO-CHH neither exhibits hyperglycaemic activity in vivo, nor does it inhibit Y-organ ecdysteroid synthesis in vitro. From the morphology of the neurons it seems likely that novel functions remain to be discovered. |
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