Purification of G Protein βγ from Bovine Brain

Dingus, Jane; Tatum, Bronwyn S.; Vaidyanathan, Govindan; Hildebrandt, John D.

doi:10.1016/s0076-6879(02)44716-7

Cited by 2 publications

(1 citation statement)

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“…Large amounts of the bg (g1 and g2) dimers (molecular masses; about 60 kDa) containing no a subunit were present in the plasma membrane in rice. The presence of such free dimers, as well as the heterotrimers, was found in mammalian brains (Dingus et al, 2002), but the physiological meaning of the situation remains unknown. The free bg (g1 and g2) dimers in rice may transmit signals to some effectors rather than doing nothing, because the Arabidopsis b subunit has been suggested to transmit signals independently of the a subunit in some developmental stages (Ullah et al, 2003).…”

Section: Discussionmentioning

confidence: 99%

Characterization of heterotrimeric G protein complexes in rice plasma membrane

et al. 2004

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SummaryTwo genes in the rice genome were identi®ed as those encoding the g subunits, g1 and g2, of heterotrimeric G proteins. Using antibodies against the recombinant proteins for the a, b, g1, and g2 subunits of the G protein complexes, all of the subunits were proven to be localized in the plasma membrane in rice. Gel ®ltration of solubilized plasma membrane proteins showed that all of the a subunits were present in large protein complexes (about 400 kDa) containing the other subunits, b, g1, and g2, and probably also some other proteins, whereas large amounts of the b and g (g1 and g2) subunits were freed from the large complexes and took a 60-kDa form. A yeast two-hybrid assay and coimmunoprecipitation experiments showed that the b subunit interacted tightly with the g1 and g2 subunits, and so the b and g subunits appeared to form dimers in rice cells. Some dimers were associated with the a subunit, because few b, g1, and g2 subunits were present in the 400-kDa complexes in a rice mutant, d1, which was lacking in the a subunit. When a constitutively active form of the a subunit was prepared by the exchange of one amino acid residue and introduced into d1, the mutagenized subunit was localized in the plasma membrane of the transformants and took a free, and not the 400-kDa, form.

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Section: Discussionmentioning

confidence: 99%