ISSN:
1471-4159
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Medicine
Notes:
Abstract : The distribution and properties in brain of the α subunits of the major bovine brain Go isoforms, GoA, GoB and GoC, were characterized. The αoA and αoB isoforms arise from alternative splicing of RNAs from a single αo gene, whereas αoC is a deamidated form of αoA. All three Go isoforms purify from brain with different populations of βγ dimers. This variable subunit composition of Go heterotrimers is likely a consequence of their functional differences. This study examined the biochemical properties of the αo isoforms to see if these properties explain the variable βγ composition of their heterotrimers. The brain distribution of αoB differed substantially from that of αoA and αoC, as did its guanine nucleotide binding properties. The unique subunit composition of GoB can be explained by its expression in different brain regions. The αoA and αoC showed slight differences in guanine nucleotide binding properties but no preference for particular βγ dimers when reassociated with a heterogeneous βγ pool. The αoC protein occurred in a constant ratio to αoA throughtout the brain, but was a much larger percent of total brain αo than previously thought, ~35%. These results suggest that αoA is a precursor of αoC and that the association of Goα subunits with different βγ dimers reflects the function of an adaptive, G-protein signaling mechanism in brain.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1046/j.1471-4159.1999.0730633.x
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