Phenotypic analysis of separation-of-function alleles of MEI-41, Drosophila ATM/ATR.
ATM/ATR kinases act as signal transducers in eukaryotic DNA damage and replication checkpoints. Mutations in ATM/ATR homologs have pleiotropic effects that range from sterility to increased killing by genotoxins in humans, mice, and Drosophila. Here we report the generation of a null allele of mei-41, Drosophila ATM/ATR homolog, and the use of it to document a semidominant effect on a larval mitotic checkpoint and methyl methanesulfonate (MMS) sensitivity. We also tested the role of mei-41 in a recently characterized checkpoint that delays metaphase/anaphase transition after DNA damage in cellular embryos. We then compare five existing mei-41 alleles to the null with respect to known phenotypes (female sterility, cell cycle checkpoints, and MMS resistance). We find that not all phenotypes are affected equally by each allele, i.e., the functions of MEI-41 in ensuring fertility, cell cycle regulation, and resistance to genotoxins are genetically separable. We propose that MEI-41 acts not in a single rigid signal transduction pathway, but in multiple molecular contexts to carry out its many functions. Sequence analysis identified mutations, which, for most alleles, fall in the poorly characterized region outside the kinase domain; this allowed us to tentatively identify additional functional domains of MEI-41 that could be subjected to future structure-function studies of this key molecule.
Laurençon
Anne
A
Molecular and Cellular Biology Department, University of California, Davis 95616, USA.
Purdy
Amanda
A
Sekelsky
Jeff
J
Hawley
R Scott
RS
Su
Tin Tin
TT
D000483:Alleles; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015153:Blotting, Western; D002453:Cell Cycle; D018797:Cell Cycle Proteins / Q000235:genetics*; D003433:Crosses, Genetic; D004249:DNA Damage; D004251:DNA Transposable Elements; D004268:DNA-Binding Proteins / Q000235:genetics*; D004305:Dose-Response Relationship, Drug; D004330:Drosophila / Q000235:genetics*; D029721:Drosophila Proteins / Q000235:genetics*; D005260:Female; D005298:Fertility; D017353:Gene Deletion; D006579:Heterozygote; D008297:Male; D008741:Methyl Methanesulfonate; D008938:Mitosis; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009153:Mutagens; D009154:Mutation; D010641:Phenotype; D010766:Phosphorylation; D010802:Phylogeny; D017346:Protein Serine-Threonine Kinases; D011995:Recombination, Genetic; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction; D013329:Structure-Activity Relationship; D014960:X Chromosome / Q000648:ultrastructure
D018797:Cell Cycle Proteins; D004251:DNA Transposable Elements; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D009153:Mutagens; D008741:Methyl Methanesulfonate; C444435:Mei-41 protein, Drosophila; D017346:Protein Serine-Threonine Kinases