Identification and cardiotropic actions of sulfakinin peptides in the American lobster Homarus americanus.
2007
SUMMARY In arthropods, a group of peptides possessing a–
Y (SO3H) GHM/LRFamide carboxy-terminal motif have been
collectively termed the sulfakinins. Sulfakinin isoforms have been identified
from numerous insect species. In contrast, members of this peptide family have
thus far been isolated from just two crustaceans, the penaeid shrimp
Penaeus monodon and Litopenaeus vannamei . Here, we report
the identification of a cDNA encoding prepro-sulfakinin from the American
lobster Homarus americanus . Two sulfakinin-like sequences were
identified within the open-reading frame of the cDNA. Based on modifications
predicted by peptide modeling programs, and on homology to the known isoforms
of sulfakinin, particularly those from shrimp, the mature H.
americanus sulfakinins were hypothesized to be
pEFDEY (SO3H) GHMRFamide (Hoa-SK I) and
GGGEY (SO3H) DDY (SO3H) GHLRFamide (Hoa-SK II). Hoa-SK I is
identical to one of the previously identified shrimp sulfakinins, while Hoa-SK
II is a novel isoform. Exogenous application of either synthetic Hoa-SK I or
Hoa-SK II to the isolated lobster heart increased both the frequency and
amplitude of spontaneous heart contractions. In preparations in which
spontaneous contractions were irregular, both peptides increased the
regularity of the heartbeat. Our study provides the first molecular
characterization of a sulfakinin-encoding cDNA from a crustacean, as well as
the first demonstration of bioactivity for native sulfakinins in this group of
arthropods.
Keywords:
- Correction
- Source
- Cite
- Save
- Machine Reading By IdeaReader
44
References
49
Citations
NaN
KQI