%0 Journal Article
%T PA1b, a plant peptide, induces intracellular [Ca2+] increase via Ca2+ influx through the L-type Ca2+ channel and triggers secretion in pancreatic β cells<br>PA1b, a plant peptide, induces intracellular [Ca2+ ] in-crease via Ca2+ influx through the L-type Ca2+ channel and triggers secretion in pancreatic β cells
%A HU ZhiTao DUN XinPeng ZHANG Ming ZHU HongLiang XIE Li WU ZhengXing CHEN ZhengWang XU Tao
%A <br>
%J 中国科学C辑(英文版)
%D 2007
%I Springer
%X Using alginic acid to adsorb polypeptides at pH 2.7, we isolated a peptide pea albumin 1b (PA1b) from pea seeds. The PA1b is a single chain peptide consisting of 37 amino acid residues with 6 cysteines which constitutes the cystine-knot structure. Using microfluorometry and patch clamp techniques, we found that PA1b significantly elevated the intracellular calcium level (Ca2+]i) and elicited membrane capacitance increase in the primary rat pancreatic β cells. The PA1b effect on Ca2+]i elevation was abolished in the absence of extracellular Ca2+ or in the presence of L-type Ca2+ channel blocker, nimodipine. Interestingly, we found that PA1b significantly depolarized membrane potential, which could lead to the opening of voltage-dependent L-type Ca2+ channels and influx of extracellular Ca2+, and then evoke robust secretion. In this study we identified the plant peptide PA1b which is capable of affecting the excitability and function of mammalian pancreatic β cell. These authors contributed equally to this work Supported by the National Natural Science Foundation of China (Grant Nos. 30370674, 30470448, and 30470646), the CAS Project (Grant No. KSCX2-SW-224), and the China “863” Program (Grant No. 2012AA214066). The laboratory of Tao Xu is also supported by the Partner Group Scheme of the Max Planck Institute for Biophysical Chemistry, G?ttingen
%K PA1b
%K pancreatic β
%K cell
%K intracellular calcium concentration
%K L-type Ca2+ channel
%K exocytosis<br>PA1b
%K pancreatic
%K β
%K cell
%K intracellular
%K calcium
%K concentration
%K L-type
%K Ca2
%K channel
%K exocytosis
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=90BA3D13E7F3BC869AC96FB3DA594E3FE34FBF7B8BC0E591&jid=180CF3A72E750F3261A8A60EDC957784&aid=00C06BF3EFE3BB12BF68368C90EBF976&yid=A732AF04DDA03BB3&vid=771152D1ADC1C0EB&iid=38B194292C032A66&sid=B8F8200D88DDC7D6&eid=6490F0E20C4B41AD&journal_id=1674-7305&journal_name=ScienceChina.Lifesciences&referenced_num=0&reference_num=23