title: Purinosome formation as a function of the cell cycle.
abstract: The de novo purine biosynthetic pathway relies on six enzymes to catalyze the conversion of phosphoribosylpyrophosphate to inosine 5'-monophosphate. Under purine-depleted conditions, these enzymes form a multienzyme complex known as the purinosome. Previous studies have revealed the spatial organization and importance of the purinosome within mammalian cancer cells. In this study, time-lapse fluorescence microscopy was used to investigate the cell cycle dependency on purinosome formation in two cell models. Results in HeLa cells under purine-depleted conditions demonstrated a significantly higher number of cells with purinosomes in the G1 phase, which was further confirmed by cell synchronization. HGPRT-deficient fibroblast cells also exhibited the greatest purinosome formation in the G1 phase; however, elevated levels of purinosomes were also observed in the S and G2/M phases. The observed variation in cell cycle-dependent purinosome formation between the two cell models tested can be attributed to differences in purine biosynthetic mechanisms. Our results demonstrate that purinosome formation is closely related to the cell cycle.
authors.affiliation: Departments of Engineering Science and Mechanics and.
authors.forename: Chung Yu
authors.initials: CY
authors.lastname: Chan
authors.affiliation: Chemistry, The Pennsylvania State University, University Park, PA 16802;
authors.forename: Hong
authors.initials: H
authors.lastname: Zhao
authors.affiliation: Chemistry, The Pennsylvania State University, University Park, PA 16802;
authors.forename: Raymond J
authors.initials: RJ
authors.lastname: Pugh
authors.affiliation: Chemistry, The Pennsylvania State University, University Park, PA 16802;
authors.forename: Anthony M
authors.initials: AM
authors.lastname: Pedley
authors.affiliation: Departments of Biochemistry and Cell Biology and Chemistry, Stony Brook University, Stony Brook, NY 11794;
authors.forename: Jarrod
authors.initials: J
authors.lastname: French
authors.affiliation: Broad Institute of MIT and Harvard, Cambridge, MA 02138;
authors.forename: Sara A
authors.initials: SA
authors.lastname: Jones
authors.affiliation: Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138; and.
authors.forename: Xiaowei
authors.initials: X
authors.lastname: Zhuang
authors.affiliation: Departments of Neurology, Human Genetics, and Pediatrics, Emory University, Atlanta, GA 30322.
authors.forename: Hyder
authors.initials: H
authors.lastname: Jinnah
authors.affiliation: Departments of Engineering Science and Mechanics and.
authors.forename: Tony Jun
authors.initials: TJ
authors.lastname: Huang
authors.affiliation: Chemistry, The Pennsylvania State University, University Park, PA 16802; sjb1@psu.edu.
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Benkovic
mesh_terms: D002453:Cell Cycle; D006367:HeLa Cells; D006801:Humans; D007041:Hypoxanthine Phosphoribosyltransferase / Q000235:genetics; D008856:Microscopy, Fluorescence; D011687:Purines / Q000096:biosynthesis*; D059010:Single-Cell Analysis
chemical_list: D011687:Purines; D007041:Hypoxanthine Phosphoribosyltransferase
keywords: cell cycle; de novo purine biosynthesis; fluorescence microscopy; metabolism; purinosome