In vivo analysis of the Drosophila light-sensitive channels, TRP and TRPL

被引:153
作者
Reuss, H [1 ]
Mojet, MH [1 ]
Chyb, S [1 ]
Hardie, RC [1 ]
机构
[1] Univ Cambridge, Dept Anat, Cambridge CB2 3DY, England
基金
英国惠康基金;
关键词
D O I
10.1016/S0896-6273(00)80416-X
中图分类号
Q189 [神经科学];
学科分类号
071006 ;
摘要
We have tested the proposal that the right-sensitive conductance in Drosophila is composed of two independent components by comparing the wild-type conductance with that in mutants lacking one or the other of the putative light-sensitive channel subunits, TRP and TRPL. For a wide range of cations, ionic permeability ratios in wild type were always intermediate between those of trp and trpl mutants. Effective channel conductances derived by noise analysis in wild type were again intermediate (17 pS; c.f. 35 pS in trp and 4 pS in trpl) and also showed a complex voltage dependence, which was quantitatively explained by the summation of TRPL and TRP channels after taking their different reversal potentials into account. Although La3+ partially blocked the light response in wild-type photoreceptors, it increased the effective single channel conductance. The results indicate that the wild-type light-activated conductance is composed of two separate channels, with the properties of TRP-and TRPL-dependent channels as determined in the respective mutants.
引用
收藏
页码:1249 / 1259
页数:11
相关论文
共 37 条
[11]   Calcium signalling: Setting store by calcium channels [J].
Hardie, RC .
CURRENT BIOLOGY, 1996, 6 (11) :1371-1373
[12]   WHOLE-CELL RECORDINGS OF THE LIGHT-INDUCED CURRENT IN DISSOCIATED DROSOPHILA PHOTORECEPTORS - EVIDENCE FOR FEEDBACK BY CALCIUM PERMEATING THE LIGHT-SENSITIVE CHANNELS [J].
HARDIE, RC .
PROCEEDINGS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES, 1991, 245 (1314) :203-210
[13]   SPONTANEOUS ACTIVATION OF LIGHT-SENSITIVE CHANNELS IN DROSOPHILA PHOTORECEPTORS [J].
HARDIE, RC ;
MINKE, B .
JOURNAL OF GENERAL PHYSIOLOGY, 1994, 103 (03) :389-407
[14]   NOVEL CA2+ CHANNELS UNDERLYING TRANSDUCTION IN DROSOPHILA PHOTORECEPTORS - IMPLICATIONS FOR PHOSPHOINOSITIDE-MEDIATED CA2+ MOBILIZATION [J].
HARDIE, RC ;
MINKE, B .
TRENDS IN NEUROSCIENCES, 1993, 16 (09) :371-376
[15]   THE TRP GENE IS ESSENTIAL FOR A LIGHT-ACTIVATED CA2+ CHANNEL IN DROSOPHILA PHOTORECEPTORS [J].
HARDIE, RC ;
MINKE, B .
NEURON, 1992, 8 (04) :643-651
[16]   THE DROSOPHILA CATION CHANNEL TRPL EXPRESSED IN INSECT SF9 CELLS IS STIMULATED BY AGONISTS OF G-PROTEIN-COUPLED RECEPTORS [J].
HARTENECK, C ;
OBUKHOV, AG ;
ZOBEL, A ;
KALKBRENNER, F ;
SCHULTZ, G .
FEBS LETTERS, 1995, 358 (03) :297-300
[17]  
Hille B., 1992, IONIC CHANNELS EXCIT
[18]  
HOCHSTRATE P, 1989, J COMP PHYSIOL A, V166, P179, DOI 10.1007/BF00193462
[19]   CALCIUM RELEASE-ACTIVATED CALCIUM CURRENT IN RAT MAST-CELLS [J].
HOTH, M ;
PENNER, R .
JOURNAL OF PHYSIOLOGY-LONDON, 1993, 465 :359-386
[20]   Expression of Drosophila trpl cRNA in Xenopus laevis oocytes leads to the appearance of a Ca2+ channel activated by Ca2+ and calmodulin, and by guanosine 5'[gamma-thio]triphosphate [J].
Lan, L ;
Bawden, MJ ;
Auld, AM ;
Barritt, GJ .
BIOCHEMICAL JOURNAL, 1996, 316 :793-803