Characterisation of the helicostatin peptide precursor gene from Helicoverpa armigera (Lepidoptera: Noctuidae)
Characterisation of the helicostatin peptide precursor gene from Helicoverpa armigera (Lepidoptera: Noctuidae)
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DOI：
10.1016/s0965-1748(99)00092-2
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发表时间：
1999-12-01
影响因子：
3.8
通讯作者：
East, P
中科院分区：
文献类型：
--
作者：
Davey, M;Duve, H;East, P
从棉铃虫基因组DNA文库中克隆了编码螺旋抑素肽家族的基因，推导的前体序列可明确鉴定所有螺旋抑素肽，并验证了先前分离的8个肽的序列。该基因由至少三个外显子组成，编码一个225个氨基酸的前体，该前体含有三个串联排列的螺旋抑素肽段，包括七个拷贝的C-末端序列-YXFGL，随后是用于羧基酰胺化的单个Gly残基。在所有可能的二元切割位点进行完全的内切蛋白水解加工，将产生先前从幼虫提取物中纯化的七种螺旋抑素八肽。如果在第三对碱性氨基酸处加工不完全，则十八肽（helicostatin IIa）也将被释放。鉴定了两种新的推定的螺旋抑素肽序列; YSKFNFGL和ERDMHRFSFGL，它们都具有C-末端五肽-FXFGL代替更常见的-YXFGL序列。与蟑螂，蝗虫和苍蝇的helicostatin前体的比较揭示了不同昆虫目的“allatostatin”前体的大小，序列和组织的变化。原位杂交组织化学证实，helicostatins在中枢神经系统的神经元和中肠的内分泌细胞中表达，这表明helicostatins是真正的脑肠肽。北方印迹分析鉴定了完整幼虫、分离的中枢神经系统和肠道组织的mRNA中的1.6kb的单个转录物。(C)1999 Elsevier Science Ltd.保留所有权利。
The gene encoding the helicostatin peptide family was isolated from a Helicoverpa armigera genomic DNA library, The deduced precursor sequence allowed unambiguous identification of all helicostatin peptides and verified the sequences of eight peptides previously isolated. The gene consists of at least three exons and encodes a precursor of 225 amino acids that contains three blocks of tandemly arranged helicostatin peptides including seven copies of the C-terminal sequence -YXFGL followed by a single Gly residue for carboxylamidation. Complete endoproteolytic processing at all possible dibasic cleavage sites would generate the seven helicostatin octapeptides previously purified from larval extracts. If processing was not complete at the third pair of basic amino acids the octadecapeptide (helicostatin IIa) would also be released. Two novel putative helicostatin peptide sequences were identified; YSKFNFGL and ERDMHRFSFGL, both of which had the C-terminal pentapeptide -FXFGL in place of the more usual -YXFGL sequence. Comparison of the helicostatin precursor with that of the cockroaches, locust and flies revealed variation in size, sequence and organisation of the 'allatostatin' precursors across different insect orders. In situ hybridisation histochemistry established that helicostatins are expressed in neurones of the central nervous system and endocrine cells of the midgut, indicating that the helicostatins are true brain-gut peptides. Northern blot analysis identified a single transcript of 1.6 kb in mRNA from whole larvae, isolated central nervous system and gut tissue. (C) 1999 Elsevier Science Ltd. All rights reserved.