G alpha q is
the alpha subunit of one of the heterotrimeric
GTP-binding proteins that mediates stimulation of phospholipase
C beta. We report the isolation and characterization of cDNA
clones from a frontal cortex cDNA library encoding
human G alpha q. The encoded protein is 359 amino acids long and is identical
in all but one amino acid residue to mouse G alpha q. Analysis of human genomic
DNA reveals an intronless sequence with strong
homology to human G alpha q cDNA. In comparison to G
alpha q cDNA, this genomic DNA sequence includes
several small deletions and insertions that alter the reading frame, multiple
single base changes, and a premature termination codon
in the open reading frame, hallmarks of a processed pseudogene.
Probes derived from human G alpha q cDNA sequence map
to both chromosomes 2 and 9 in high-stringency genomic blot analyses of DNA
from a panel of human-rodent hybrid cell lines. PCR primers that selectively
amplify the pseudogene sequence generate a product
only when DNA containing human chromosome 2 is used as the template, indicating
that the authentic G alpha q gene (GNAQ) is located on chromosome 9. Regional
localization by FISH analysis places GNAQ at 9q21 and the pseudogene
at 2q14.3-q21.
PMID: 8825633 [PubMed - indexed for MEDLINE]