Isolation and characterization of the human AKT1 gene, identification of 13 single nucleotide polymorphisms (SNPs), and their lack of association with Type II diabetes.
OBJECTIVE
AKT1, a serine/threonine protein kinase, is an important downstream target of the insulin-signalling pathway, with both anti-apoptotic and peripheral metabolic effects. Because impaired insulin signalling is a major hallmark of Type II (non-insulin-dependent) diabetes mellitus, we considered whether the AKT1 gene could be a candidate gene involved in susceptibility of this condition. To test this possibility, we isolated and characterized the human AKT1 gene. We also looked for single nucleotide polymorphisms in the gene and examined their association with Type II diabetes mellitus in the Ashkenazi Jewish population.


METHODS
Human BAC/P1 genomic libraries were screened to isolate the AKT1 gene. To obtain structural information and the sequences of the exon-intron boundaries, BAC/P1 clones were directly sequenced. Identification of single nucleotide polymorphisms was done by polymerase chain reaction of each exon, followed by denaturing high performance liquid chromatography. Six single nucleotide polymorphisms were genotyped in Ashkenazi Jewish patients with Type II diabetes mellitus and in control subjects.


RESULTS
The human AKT1 gene was at least 24.6 kb in length and comprised 14 exons. Altogether 13 putative intragenic single nucleotide polymorphisms, with minor-allele frequencies ranging from 0.011 to 0.354, were identified. The allelic and the genotypic frequencies of 6 single nucleotide polymorphisms were the same in diabetic patients and in control subjects.


CONCLUSIONS
The results of our studies show that the AKT1 gene is not a major contributor to susceptibility to Type II diabetes mellitus in Ashkenazi Jews.
Matsubara
A
A
Division of Metabolism, Endocrinology and Diabetes, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
Wasson
J C
JC
Donelan
S S
SS
Welling
C M
CM
Glaser
B
B
Permutt
M A
MA
D001483:Base Sequence; D003001:Cloning, Molecular; D017931:DNA Primers; D003924:Diabetes Mellitus, Type 2 / Q000235:genetics*; D005091:Exons; D020022:Genetic Predisposition to Disease; D015698:Genomic Library; D006801:Humans; D007328:Insulin / Q000502:physiology; D007438:Introns; D007585:Jews / Q000235:genetics; D015810:Linkage Disequilibrium; D016133:Polymerase Chain Reaction; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D017346:Protein Serine-Threonine Kinases / Q000235:genetics*; D011518:Proto-Oncogene Proteins; D051057:Proto-Oncogene Proteins c-akt; D012016:Reference Values; D015183:Restriction Mapping; D015398:Signal Transduction
D017931:DNA Primers; D007328:Insulin; D011518:Proto-Oncogene Proteins; C494918:AKT1 protein, human; D017346:Protein Serine-Threonine Kinases; D051057:Proto-Oncogene Proteins c-akt