The world's first wiki where authorship really matters (Nature Genetics, 2008). Due credit and reputation for authors. Imagine a global collaborative knowledge base for original thoughts. Search thousands of articles and collaborate with scientists around the globe.

wikigene or wiki gene protein drug chemical gene disease author authorship tracking collaborative publishing evolutionary knowledge reputation system wiki2.0 global collaboration genes proteins drugs chemicals diseases compound
Hoffmann, R. A wiki for the life sciences where authorship matters. Nature Genetics (2008)



Gene Review

grp  -  grapes

Drosophila melanogaster

Synonyms: 1C, CG17161, CHK1, CHK1/Grapes, Chk1, ...
Welcome! If you are familiar with the subject of this article, you can contribute to this open access knowledge base by deleting incorrect information, restructuring or completely rewriting any text. Read more.

High impact information on grp

  • In the absence of hydroxyurea, a G2 checkpoint delay occurred in cnd2-1 mutants in a manner dependent on Cds1 and ATM-like Rad3, but not Chk1 (refs 10-13), before the mitotic condensation defect [1].
  • Here we show that mutations in the grapes (grp) checkpoint 1 kinase homologue in Drosophila block the morphological and biochemical changes that accompany the midblastula transition, lead to a continuation of the maternal cell-cycle programme, and disrupt DNA-replication checkpoint control of cell-cycle progression [2].
  • Our results suggest that these condensation defects, rather than incomplete DNA replication, are responsible for the extensive metaphase delays observed in grp-derived embryos [3].
  • Therefore, grp condensation defects are not a direct consequence of entering metaphase with incompletely replicated chromosomes [3].
  • To clarify the relationship between these phenotypes, we simultaneously timed multiple nuclear and cytoplasmic events in mutant grp-derived embryos [3].

Biological context of grp


Anatomical context of grp


Associations of grp with chemical compounds


Regulatory relationships of grp

  • In other systems, Chk1 kinase phosphorylates and suppresses the activity of Cdc25 phosphatase: the resulting failure to remove inhibitory phosphate from cyclin-dependent kinase 1 (Cdk1) prevents entry into mitosis [4] [5] [11].

Other interactions of grp

  • To test this, we genetically reduced mitotic cyclin levels and also examined repair in grp (DmChk1) and lok (DmChk2) mutants [12].
  • Like mei-41 and grp, Dwee1 is zygotically dispensable but is required maternally for completing the embryonic nuclear cycles [7].
  • Because in Drosophila embryos Cdk1 lacks inhibitory phosphate during cycles 11-13 [6], it is not clear that known actions of Grp/Chk1 suffice in these cycles [11].
  • We found that the loss of grp compromised cyclin A proteolysis and delayed mitotic disjunction of sister chromosomes [11].


  1. Cnd2 has dual roles in mitotic condensation and interphase. Aono, N., Sutani, T., Tomonaga, T., Mochida, S., Yanagida, M. Nature (2002) [Pubmed]
  2. DNA-replication checkpoint control at the Drosophila midblastula transition. Sibon, O.C., Stevenson, V.A., Theurkauf, W.E. Nature (1997) [Pubmed]
  3. The Grapes checkpoint coordinates nuclear envelope breakdown and chromosome condensation. Yu, K.R., Saint, R.B., Sullivan, W. Nat. Cell Biol. (2000) [Pubmed]
  4. Chk2 regulates irradiation-induced, p53-mediated apoptosis in Drosophila. Peters, M., DeLuca, C., Hirao, A., Stambolic, V., Potter, J., Zhou, L., Liepa, J., Snow, B., Arya, S., Wong, J., Bouchard, D., Binari, R., Manoukian, A.S., Mak, T.W. Proc. Natl. Acad. Sci. U.S.A. (2002) [Pubmed]
  5. ATM and ATR Pathways Signal Alternative Splicing of Drosophila TAF1 Pre-mRNA in Response to DNA Damage. Katzenberger, R.J., Marengo, M.S., Wassarman, D.A. Mol. Cell. Biol. (2006) [Pubmed]
  6. The Drosophila ATM homologue Mei-41 has an essential checkpoint function at the midblastula transition. Sibon, O.C., Laurençon, A., Hawley, R., Theurkauf, W.E. Curr. Biol. (1999) [Pubmed]
  7. Drosophila wee1 has an essential role in the nuclear divisions of early embryogenesis. Price, D., Rabinovitch, S., O'Farrell, P.H., Campbell, S.D. Genetics (2000) [Pubmed]
  8. The Drosophila maternal-effect mutation grapes causes a metaphase arrest at nuclear cycle 13. Fogarty, P., Kalpin, R.F., Sullivan, W. Development (1994) [Pubmed]
  9. chk-1 is an essential gene and is required for an S-M checkpoint during early embryogenesis. Kalogeropoulos, N., Christoforou, C., Green, A.J., Gill, S., Ashcroft, N.R. Cell Cycle (2004) [Pubmed]
  10. The Drosophila grapes gene is related to checkpoint gene chk1/rad27 and is required for late syncytial division fidelity. Fogarty, P., Campbell, S.D., Abu-Shumays, R., Phalle, B.S., Yu, K.R., Uy, G.L., Goldberg, M.L., Sullivan, W. Curr. Biol. (1997) [Pubmed]
  11. Drosophila grapes/CHK1 mutants are defective in cyclin proteolysis and coordination of mitotic events. Su, T.T., Campbell, S.D., O'Farrell, P.H. Curr. Biol. (1999) [Pubmed]
  12. Drosophila ATR in Double-Strand Break Repair. Larocque, J.R., Jaklevic, B., Su, T.T., Sekelsky, J. Genetics (2007) [Pubmed]
WikiGenes - Universities