tailieunhanh - Báo cáo khoa học: Tachykinin-related peptide precursors in two cockroach species Molecular cloning and peptide expression in brain neurons and intestine

Tachykinins and tachykinin-related peptides (TKRPs) play major roles in signaling in the nervous system and intestine of both invertebrates and ver-tebrates. Here we have identified cDNAs encoding precursors of multiple TKRPs from the cockroachesLeucophaea maderaeandPeriplaneta ameri-cana. All nine LemTKRPs that had been chemically isolated in earlier experiments could be identified on the precursor ofL. maderae. Four previ-ously unidentified LemTKRPs were found in addition on the precursor. | ềFEBS Journal Tachykinin-related peptide precursors in two cockroach species Molecular cloning and peptide expression in brain neurons and intestine Reinhard Predel1 Susanne Neupert1 Steffen Roth1 Christian Derst1 and Dick R. Nassel2 1 Saxon Academy of Sciences Research Group Jena Germany 2 Department of Zoology Stockholm University Sweden Keywords brain-gut peptides insect neuropeptide neurochemistry mass spectrometry Periplaneta americana Leucophaea maderae Correspondence R. Predel Saxon Academy of Sciences Research Group Jena ErbertstraBe 1 07743 Jena Germany Tel 49 3641 94919I Fax 49 3641 949192 E-mail B6PRRE@ Received 1 March 2005 revised 22 April 2005 accepted 6 May 2005 doi Tachykinins and tachykinin-related peptides TKRPs play major roles in signaling in the nervous system and intestine of both invertebrates and vertebrates. Here we have identified cDNAs encoding precursors of multiple TKRPs from the cockroaches Leucophaea maderae and Periplaneta americana. All nine LemTKRPs that had been chemically isolated in earlier experiments could be identified on the precursor of L. maderae. Four previously unidentified LemTKRPs were found in addition on the precursor. The P. americana cDNA displayed an open reading frame very similar to that of L. maderae with 13 different TKRPs. MALDI-TOF mass spectra from tissues of both species confirms the presence of all the TKRPs encoded on the precursor plus two additional peptides that are cleavage products of the N-terminally extended TKRPs. A tissue-specific distribution of TKRPs was observed in earlier experiments at isolation from brain and midgut of L. maderae. Our data do not suggest a differential gene expression but a different efficacy in processing of LemTKRP-2 and Lem PeaTKRP-3 in the brain and intestine respectively. This results in a gut-specific accumulation of these extended peptides whereas in the brain their cleavage products LemTKRP-1 and LemTKRP-311-19 .