Identification and cardiotropic actions of sulfakinin peptides in the American lobster Homarus americanus
Identification and cardiotropic actions of sulfakinin peptides in the American lobster Homarus americanus
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DOI：
10.1242/jeb.004770
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发表时间：
2007-07-01
影响因子：
2.8
通讯作者：
Christie, Andrew E.
中科院分区：
文献类型：
--
作者：
Dickinson, Patsy S.;Stevens, Jake S.;Christie, Andrew E.
在节肢动物中，一组具有-Y（（SO 3 H））GHM/LRF酰胺羧基末端基序的肽被统称为磺胺激肽。已从许多昆虫物种中鉴定出磺胺激肽同种型。相比之下，该肽家族的成员迄今仅从两种甲壳类动物中分离出，即斑节对虾和凡纳滨对虾。在这里，我们报告的cDNA编码前磺激酶从美国龙虾Homarus americanus的鉴定。在cDNA的开放阅读框内鉴定了两个磺胺激肽样序列。基于肽模拟程序预测的修饰，以及与已知的磺胺激肽异构体的同源性，特别是来自虾的那些，成熟的H。假设美洲磺胺激肽是pEFDEY（（SO 3 H））GHMRFamide（Hoa-SK I）和GGGEY（（SO 3 H））DDY（SO 3 H）GHLRFamide（Hoa-SK II）。Hoa-SK I与先前鉴定的虾磺胺激肽之一相同，而Hoa-SK II是一种新的同种型。外源性应用的合成Hoa-SK I或Hoa-SK II的孤立的龙虾心脏增加的频率和幅度的自发心脏收缩。在自发收缩不规则的准备中，两种肽都增加了心跳的规律性。我们的研究提供了第一个从甲壳类动物的磺胺激肽编码的cDNA的分子特征，以及第一次证明在这组节肢动物的天然磺胺激肽的生物活性。
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.