title: Small molecules that delay S phase suppress a zebrafish bmyb mutant.
abstract: Bmyb is a ubiquitously expressed transcription factor involved in cellular proliferation and cancer. Loss of bmyb function in the zebrafish mutant crash&burn (crb) results in decreased cyclin B1 expression, mitotic arrest and genome instability. These phenotypic observations in crb mutants could be attributed to the decreased expression of cyclin B1, a cell-cycle regulatory protein that is responsible for driving cell progression from G2 through mitosis. To identify small molecules that interact with the bmyb pathway, we developed an embryo-based suppressor screening strategy. In 16 weeks we screened a diverse approximately 16,000 compound library, and discovered one previously unknown compound, persynthamide (psy, 1), that suppressed bmyb-dependent mitotic defects. Psy-treated embryos showed an S-phase delay, and knockdown of the cell-cycle checkpoint regulator ataxia telangiectasia--and Rad-related kinase (ATR) abrogated the suppression of crb. The DNA synthesis inhibitors aphidicolin (2) and hydroxyurea (3) also suppressed crb. S-phase inhibition upregulated cyclin B1 mRNA, promoting the progression of cells through mitosis. Our study demonstrates that chemical suppressor screening in zebrafish can identify compounds with cell-cycle activity and can be used to identify pathways that interact with specific cell-cycle phenotypes.
authors.affiliation: Department of Pathology, Brigham and Women's Hospital, 75 Francis Street, Boston, Massachusetts 02115, USA.
authors.forename: Howard M
authors.initials: HM
authors.lastname: Stern
authors.forename: Ryan D
authors.initials: RD
authors.lastname: Murphey
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Shepard
authors.forename: James F
authors.initials: JF
authors.lastname: Amatruda
authors.forename: Christian T
authors.initials: CT
authors.lastname: Straub
authors.forename: Kathleen L
authors.initials: KL
authors.lastname: Pfaff
authors.forename: Gerhard
authors.initials: G
authors.lastname: Weber
authors.forename: John A
authors.initials: JA
authors.lastname: Tallarico
authors.forename: Randall W
authors.initials: RW
authors.lastname: King
authors.forename: Leonard I
authors.initials: LI
authors.lastname: Zon
mesh_terms: D000218:Adamantane / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology; D000818:Animals; D002453:Cell Cycle / Q000187:drug effects / Q000502:physiology; D019926:Cyclin B / Q000187:drug effects / Q000235:genetics; D056744:Cyclin B1; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D008938:Mitosis / Q000187:drug effects; D009154:Mutation; D010641:Phenotype; D020598:Proto-Oncogene Proteins c-myb / Q000235:genetics* / Q000378:metabolism; D011725:Pyridines / Q000737:chemistry / Q000494:pharmacology*; D012333:RNA, Messenger / Q000187:drug effects / Q000235:genetics; D016196:S Phase / Q000187:drug effects / Q000235:genetics*; D015027:Zebrafish / Q000196:embryology / Q000235:genetics* / Q000254:growth & development
chemical_list: D019926:Cyclin B; D056744:Cyclin B1; D020598:Proto-Oncogene Proteins c-myb; D011725:Pyridines; D012333:RNA, Messenger; C507216:persynthamide; D000218:Adamantane