Characterization of RNA primers synthesized by the human breast cancer cell DNA synthesome. 2009

Heqiao Dai, and Jianying Liu, and Linda H Malkas, and Robert J Hickey
Department of Medicine, Division of Hematology/Oncology, Indiana University School of Medicine, Indiana University Cancer Research Institute, Indiana University Simon Cancer Center, 1044 W. Walnut Street R4-170 Indianapolis, Indiana 46202, USA.

We previously reported on the purification and characterization of a functional multi-protein DNA replication complex (the DNA synthesome) from human cells and tissues. The synthesome is fully competent to carry-out all phases of the DNA replication process in vitro. In this study, DNA primase, a component of the synthesome, is examined to determine its activity and processivity in the in vitro synthesis and extension of RNA primers. Our results show that primase activity in the P4 fraction of the synthesome is 30-fold higher than that of crude cell extracts. The synthesome synthesizes RNA primers that are 7-10 ribonucleotides long and DNA primers that are 20-40 deoxyribonucleotides long using a poly(dT) template of exogenous single-stranded DNA. The synthesome-catalyzed RNA primers can be elongated by E. coli DNA polymerase I to form the complementary DNA strands on the poly(dT) template. In addition, the synthesome also supports the synthesis of native RNA primers in vitro using an endogenous supercoiled double-stranded DNA template. Gel analysis demonstrates that native RNA primers are oligoribonucleotides of 10-20 nt in length and the primers are covalently link to DNA to form RNA-primed nascent DNA of 100-200 nt. Our study reveals that the synthesome model is capable of priming and continuing DNA replication. The ability of the synthesome to synthesize and extend RNA primers in vitro elucidates the organizational and functional properties of the synthesome as a potentially useful replication apparatus to study the function of primase and the interaction of primase with other replication proteins.

UI MeSH Term Description Entries
D009097 Multienzyme Complexes Systems of enzymes which function sequentially by catalyzing consecutive reactions linked by common metabolic intermediates. They may involve simply a transfer of water molecules or hydrogen atoms and may be associated with large supramolecular structures such as MITOCHONDRIA or RIBOSOMES. Complexes, Multienzyme
D001943 Breast Neoplasms Tumors or cancer of the human BREAST. Breast Cancer,Breast Tumors,Cancer of Breast,Breast Carcinoma,Cancer of the Breast,Human Mammary Carcinoma,Malignant Neoplasm of Breast,Malignant Tumor of Breast,Mammary Cancer,Mammary Carcinoma, Human,Mammary Neoplasm, Human,Mammary Neoplasms, Human,Neoplasms, Breast,Tumors, Breast,Breast Carcinomas,Breast Malignant Neoplasm,Breast Malignant Neoplasms,Breast Malignant Tumor,Breast Malignant Tumors,Breast Neoplasm,Breast Tumor,Cancer, Breast,Cancer, Mammary,Cancers, Mammary,Carcinoma, Breast,Carcinoma, Human Mammary,Carcinomas, Breast,Carcinomas, Human Mammary,Human Mammary Carcinomas,Human Mammary Neoplasm,Human Mammary Neoplasms,Mammary Cancers,Mammary Carcinomas, Human,Neoplasm, Breast,Neoplasm, Human Mammary,Neoplasms, Human Mammary,Tumor, Breast
D004259 DNA-Directed DNA Polymerase DNA-dependent DNA polymerases found in bacteria, animal and plant cells. During the replication process, these enzymes catalyze the addition of deoxyribonucleotide residues to the end of a DNA strand in the presence of DNA as template-primer. They also possess exonuclease activity and therefore function in DNA repair. DNA Polymerase,DNA Polymerases,DNA-Dependent DNA Polymerases,DNA Polymerase N3,DNA Dependent DNA Polymerases,DNA Directed DNA Polymerase,DNA Polymerase, DNA-Directed,DNA Polymerases, DNA-Dependent,Polymerase N3, DNA,Polymerase, DNA,Polymerase, DNA-Directed DNA,Polymerases, DNA,Polymerases, DNA-Dependent DNA
D004261 DNA Replication The process by which a DNA molecule is duplicated. Autonomous Replication,Replication, Autonomous,Autonomous Replications,DNA Replications,Replication, DNA,Replications, Autonomous,Replications, DNA
D005260 Female Females
D006801 Humans Members of the species Homo sapiens. Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D012313 RNA A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. (Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed) RNA, Non-Polyadenylated,Ribonucleic Acid,Gene Products, RNA,Non-Polyadenylated RNA,Acid, Ribonucleic,Non Polyadenylated RNA,RNA Gene Products,RNA, Non Polyadenylated
D045744 Cell Line, Tumor A cell line derived from cultured tumor cells. Tumor Cell Line,Cell Lines, Tumor,Line, Tumor Cell,Lines, Tumor Cell,Tumor Cell Lines
D017931 DNA Primers Short sequences (generally about 10 base pairs) of DNA that are complementary to sequences of messenger RNA and allow reverse transcriptases to start copying the adjacent sequences of mRNA. Primers are used extensively in genetic and molecular biology techniques. DNA Primer,Oligodeoxyribonucleotide Primer,Oligodeoxyribonucleotide Primers,Oligonucleotide Primer,Oligonucleotide Primers,Primer, DNA,Primer, Oligodeoxyribonucleotide,Primer, Oligonucleotide,Primers, DNA,Primers, Oligodeoxyribonucleotide,Primers, Oligonucleotide
D019915 DNA Primase A single-stranded DNA-dependent RNA polymerase that functions to initiate, or prime, DNA synthesis by synthesizing oligoribonucleotide primers. EC 2.7.7.-. Primase,Bacteriophage T7 Gene 4 Protein,DnaG (Primase),DnaG Gene Product,DnaG Protein,T7 DNA Primase-Helicase Protein,T7 DNA-Priming Protein,T7 gene-4 protein,DNA-Priming Protein, T7,Primase, DNA,Protein, T7 DNA-Priming,T7 DNA Primase Helicase Protein,T7 DNA Priming Protein,T7 gene 4 protein

Related Publications

Heqiao Dai, and Jianying Liu, and Linda H Malkas, and Robert J Hickey
January 1996, Oncology research,
Heqiao Dai, and Jianying Liu, and Linda H Malkas, and Robert J Hickey
January 2000, Cancer chemotherapy and pharmacology,
Heqiao Dai, and Jianying Liu, and Linda H Malkas, and Robert J Hickey
July 2005, Journal of pediatric surgery,
Heqiao Dai, and Jianying Liu, and Linda H Malkas, and Robert J Hickey
January 2000, Cancer chemotherapy and pharmacology,
Heqiao Dai, and Jianying Liu, and Linda H Malkas, and Robert J Hickey
August 1997, Toxicology and applied pharmacology,
Heqiao Dai, and Jianying Liu, and Linda H Malkas, and Robert J Hickey
September 1972, Nature: New biology,
Heqiao Dai, and Jianying Liu, and Linda H Malkas, and Robert J Hickey
January 1997, Oncology research,
Heqiao Dai, and Jianying Liu, and Linda H Malkas, and Robert J Hickey
January 1998, Nucleic acids research,
Heqiao Dai, and Jianying Liu, and Linda H Malkas, and Robert J Hickey
June 2022, Scientific reports,
Heqiao Dai, and Jianying Liu, and Linda H Malkas, and Robert J Hickey
June 1997, Leukemia research,
Copied contents to your clipboard!