Light-regulated localization of the beta-subunit of Gq-type G-protein in the crayfish photoreceptors

被引：0

作者：

A. Terakita

H. Takahama

T. Hariyama

T. Suzuki

Y. Tsukahara

机构：

[1] Institute of Biology,

[2] Oita University,undefined

[3] Oita 870-11,undefined

[4] Japan,undefined

[5] Department of Pharmacology,undefined

[6] Hyogo College of Medicine,undefined

[7] Nishinomiya 663,undefined

[8] Japan,undefined

[9] Graduate School of Information Sciences,undefined

[10] SKK Building,undefined

[11] Tohoku University,undefined

[12] Sendai 980-77,undefined

[13] Japan,undefined

[14] Graduate School of Information Sciences,undefined

[15] SKK Building,undefined

[16] Tohoku University,undefined

[17] Sendai 980-77 and Photodynamics Research Center,undefined

[18] The Institute of Chemical and Physical Research (RIKEN),undefined

[19] Aoba-ku Koeji,undefined

[20] Sendai 980,undefined

[21] Japan,undefined

来源：

Journal of Comparative Physiology A | 1998年 / 183卷

关键词：

Key words Photoreceptor cell; Rhabdom; β subunit of Gq; Phototransduction; Crayfish;

D O I：

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学科分类号：

摘要：

In crayfish photoreceptor cells, Gq-type G-protein plays a central role in the phototransduction pathway, and the translocation of Gqα has been proposed as one of the molecular mechanisms to control photoreceptor sensitivity. We here investigated β subunit of Gq and its localization profiles under various light conditions in the crayfish photoreceptor cells to understand the functional characteristic of visual Gq in the phototransduction pathway. An immunoprecipitation experiment was performed using an anti-Gqα antibody and a thiol-cleavable crosslinker. A 39 kDa protein was co-immunoprecipitated with Gqα, but not by irradiation, in the presence of GTPγS. The partial amino acid sequence of the 39 kDa protein was similar to Gβe in Drosophila photoreceptors, indicating that the crayfish Gβ which combines with Gqα is a Gβe homologue. Immunohistochemical and immunoblot analyses revealed that the amount of the Gβ decreased in the rhabdomeric membranes and increased in the cytoplasm in the light, compared with that in the dark. The profile of the translocation was similar to that reported for Gqα. Since both α and βγ subunits are necessary for G-proteins to be activated by rhodopsin in the rhabdom, the light-modulated translocation of a Gβe homologue possibly controls the amount of Gq which can be activated by light-stimulated rhodopsin.

引用

页码：411 / 417

页数：6