title: Increased levels of the cell cycle inhibitor protein, dacapo, accompany 20-hydroxyecdysone-induced G1 arrest in a mosquito cell line.
abstract: When treated with the steroid hormone 20-hydroxyecdysone (20E), C7-10 cells from the mosquito, Aedes albopictus, arrest in the G1 phase of the cell cycle. To explore whether 20E-mediated cell cycle arrest proceeds through increased levels of cell cycle inhibitor (CKI) proteins, we cloned the Ae. albopictus homolog of dacapo, the single member of the Cip/Kip family of CKI proteins known from Drosophila melanogaster. The Ae. albopictus dacapo cDNA encoded a 261-amino acid homolog of the Aedes aegypti protein XP_001651102.1, which is encoded by an ∼23 kb gene containing three exons. Like dacapo from D. melanogaster, the ∼27 kDa protein from Aedes and Culex mosquitoes contained several S/TXXE/D motifs corresponding to potential protein kinase CK2 phosphorylation sites, and a binding site for proliferating cell nuclear antigen (PCNA). When extracts from cells treated with 20E were analyzed by western blotting, using a primary antibody to synthetic peptides from the mosquito dacapo protein, up-regulation of an ∼27 kDa protein was observed within 24 h, and the abundance of the protein further increased by 48 h after hormone treatment. This is the first investigation of a cell cycle inhibitory protein in mosquitoes. The results reinforce growing evidence that 20E affects expression of proteins that regulate cell cycle progression.
authors.affiliation: Department of Entomology, University of Minnesota, St. Paul, USA.
authors.forename: Anna
authors.initials: A
authors.lastname: Gerenday
authors.forename: Ann M
authors.initials: AM
authors.lastname: Fallon
mesh_terms: D000330:Aedes / Q000737:chemistry / Q000166:cytology / Q000502:physiology*; D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D018844:Cyclin-Dependent Kinases / Q000037:antagonists & inhibitors*; D018076:DNA, Complementary / Q000302:isolation & purification; D029721:Drosophila Proteins / Q000737:chemistry; D004441:Ecdysterone / Q000502:physiology*; D016193:G1 Phase; D019476:Insect Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000737:chemistry; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
chemical_list: D018076:DNA, Complementary; D029721:Drosophila Proteins; D019476:Insect Proteins; D009687:Nuclear Proteins; C103336:dap protein, Drosophila; D004441:Ecdysterone; D018844:Cyclin-Dependent Kinases