Cellular localisation of the ataxia-telangiectasia (ATM) gene product and discrimination between mutated and normal forms.
The recently cloned gene (ATM) mutated in the human genetic disorder ataxia-telangiectasia (A-T) is involved in DNA damage response at different cell cycle checkpoints and also appears to have a wider role in signal transduction. Antibodies prepared against peptides from the predicted protein sequence detected a approximately 350 kDa protein corresponding to the open reading frame, which was absent in 13/23 A-T homozygotes. Subcellular fractionation, immunoelectronmicroscopy and immunofluorescence showed that the ATM protein is present in the nucleus and cytoplasmic vesicles. This distribution did not change after irradiation. We also provide evidence that ATM protein binds to p53 and this association is defective in A-T cells compatible with the defective p53 response in these cells. These results provide further support for a role for the ATM protein as a sensor of DNA damage and in a more general role in cell signalling, compatible with the broader phenotype of the syndrome.
Watters
D
D
Queensland Institute of Medical Research, P.O. Royal Brisbane Hospital, Herston, Australia.
Khanna
K K
KK
Beamish
H
H
Birrell
G
G
Spring
K
K
Kedar
P
P
Gatei
M
M
Stenzel
D
D
Hobson
K
K
Kozlov
S
S
Zhang
N
N
Farrell
A
A
Ramsay
J
J
Gatti
R
R
Lavin
M
M
D000906:Antibodies; D001260:Ataxia Telangiectasia / Q000235:genetics*; D064007:Ataxia Telangiectasia Mutated Proteins; D015153:Blotting, Western; D018797:Cell Cycle Proteins; D002461:Cell Line, Transformed; D002467:Cell Nucleus / Q000648:ultrastructure; D003001:Cloning, Molecular; D003594:Cytoplasmic Granules / Q000648:ultrastructure; D004268:DNA-Binding Proteins; D004797:Enzyme-Linked Immunosorbent Assay; D004854:Herpesvirus 4, Human; D006720:Homozygote; D006801:Humans; D016253:Microscopy, Immunoelectron; D008861:Microsomes / Q000648:ultrastructure; D016366:Open Reading Frames; D015388:Organelles / Q000378:metabolism / Q000648:ultrastructure*; D017354:Point Mutation; D014176:Protein Biosynthesis; D017346:Protein Serine-Threonine Kinases; D011506:Proteins / Q000032:analysis; D011994:Recombinant Proteins / Q000032:analysis / Q000096:biosynthesis; D017384:Sequence Deletion; D016159:Tumor Suppressor Protein p53 / Q000032:analysis; D025521:Tumor Suppressor Proteins
D000906:Antibodies; D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D011506:Proteins; D011994:Recombinant Proteins; D016159:Tumor Suppressor Protein p53; D025521:Tumor Suppressor Proteins; C576324:ATM protein, human; D064007:Ataxia Telangiectasia Mutated Proteins; D017346:Protein Serine-Threonine Kinases