Assistant Professor

Adjunct Assistant Professor
Department of Pathology
Mount Sinai School of Medicine
New York, NY

Lewis Hall, #3152
Office: (757) 446-5684
Email: This e-mail address is being protected from spambots. You need JavaScript enabled to view it

Biomedical Sciences Program Track: Molecular Integrative Biosciences (MIB)

Education

• B.S., Lynchburg College, Lynchburg, VA
• M.S., Longwood College, Farmville, VA
• Ph.D., City University of New York, New York, NY
• Postdoctoral Training, Mount Sinai School of Medicine and The Rockefeller University, New York, NY

Research Interests

Applications accepted from committed researchers.

Our research is an exploration of molecular mechanisms underlying eukaryotic DNA replication and how these mechanisms are targeted during cancer progression. Discovery at this level is aimed at translation into clinical studies for the prevention and treatment of cancer and the bioengineering of novel protein applications. We use both cell culture and human pathology specimens to perform studies that compliment each other. These studies involve various cellular, molecular, biochemical and biophysical approaches.

Molecular, cellular and biochemical analysis of MCM8 function:

The role of the minichromosome maintenance (MCM) proteins in initiation of DNA replication has been extensively studied, and the MCM2-7 toroid is proposed to be a replicative helicase unwinding DNA ahead of the replication fork during S phase. Additional functions are currently being ascribed to these family members. In 2003, we discovered the gene for MCM8, a new family member that is not found in yeast, but which has seemly evolved to adapt to the more complex nuclear structure of higher eukaryotes. We, and others, have shown the MCM8 gene to be either mutated or variantly spliced in a choriocarcinoma and virally interrupted in a hepatocarcinoma, respectively. We have reported that MCM8 is reduced in colon cancer. We are performing in vitro biochemical characterization of MCM8 activity relating to DNA replication and repair. Through such techniques as immunoprecipitation, electron microscopy, confocal microscopy and mass spectrometry, we are also identifying functional interactions of MCM8 with components of the replisome and with cellular regulators. We verify the simultaneous presence of two proteins at genomic sequences representing a characterized origin of replication using double chromatin immunoprecipitation (ChIP) procedure. We are applying information from the various analyses to studies of MCM8 interplay with regulatory pathways within the cell using mouse and human models.

We have collected ovarian cancer specimens and prepared breast organoids to model studies complementary to our cell culture studies. When possible, we match normal and tumor specimens from the same patient. Using the techniques of immunohistochemistry, dual immunofluorescence microscopy, laser capture microdissection combined with real-time RT- PCR and expression arrays, we are examining MCM8 expression at the level of both RNA and protein. These studies complement knockdown and mutational studies derived from our cell culture models.

Selected Publications

• Dianne C. Daniel and Edward M. Johnson. (2011) Addressing the Enigma of MCM8 in DNA Replication, In Jelena Kušić-Tišma (Ed.) Fundamental Aspects of DNA Replication. ISBN: 978-953-307-259-3, InTech, pp.37-52.
  
  
• Kinoshita Y, Johnson EM, Gordon RE, Negri-Bell H, Evans MT, Coolbaugh J, Rosario-Peralta Y, Samet J, Slusser E, Birkenbach MP, Daniel DC. (2008) Colocalization of MCM8 and MCM7 With Proteins Involved in Distinct Aspects of DNA Replication. Microsc Res Tech, 71 288-297. PMID: 18072282
  
  
• Daniel DC, Kinoshita Y, Khan MA, Del Valle L, Khalili K, Rappaport J and Johnson EM. (2004) Internalization of Exogenous Human Immunodeficiency Virus-1 Protein, Tat, by KG-1 Oligodendroglioma Cells Followed by Stimulation of DNA Replication Initiated at the JC Virus Origin. DNA Cell Biol, 23 (12): 858 – 867. PMID: 15684713
  
  
• Johnson EM, Kinoshita Y, Daniel DC. (2003) A new member of the MCM protein family encoded by the human MCM8 gene, located contrapodal to GCD10 at chromosome band 20p12.3-13. Nucleic Acids Res, 31 (11): 2915 – 2925. PMID: 12771218
  
  
• Khalili K, Del Valle L, Muralidharan V, Gault WJ, Darbinian N, Otte J, Meier E, Johnson EM, Daniel DC, Kinoshita Y, Amini S and Gordon J. (2003) Pur-alpha is essential for postnatal brain development and developmentally-coupled cellular proliferation as revealed by genetic inactivation in the mouse. Mol Cell Biol, 23 (19): 6857–6875. PMC193944
  
  
• Daniel DC. (2003) Comment Article. BRCA1 and BRCA2 proteins in cell function. In: Wolvey W. (Ed.) Breast Cancer. London, Current Medical Literature Ltd., pp 1–9.
  
  
• Daniel DC. (2002) Highlight: BRCA1 and BRCA2 proteins in breast cancer. Microsc Res Tech, 2002, 59 (1): 68–83. PMID: 12242698
  
  
• Daniel DC. (2002) Editorial. Breast Cancer: cell biology, clinical parameters and imaging. Microsc Res Tech, 59 (1): 1-2. DOI: 10.1002/jemt.10171
  
  
• Daniel DC, Wortman MJ, Schiller RJ, Liu H, Gan L, Mellon JS, Chang CF, Gallia GL, Rappaport J, Khalili K, Johnson EM. (2001) Coordinate effects of human immunodeficiency virus type-1 protein, Tat, and cellular protein, Pur-alpha, on DNA replication initiated at the JC virus origin. J Gen Virol, 82 (Pt7): 1543 – 1553. PMID: 11413364
  
  
• Daniel DC. (1999) Dual immunofluorescence labeling with cell-specific markers localizes BRCA1 in both basal and luminal epithelial cells in primary outgrowth from noncancerous mammary ductal and alveolar preparations. Cell Tissue Res, 298 (3): 481– 487. PMID: 10639738
  
  
• Berberich S, Trivedi A, Daniel DC, Johnson EM and Leffak M. (1995) In Vitro Replication of Plasmids Containing Human c-myc DNA. J Mol Biol, 245 (2): 92–109. PMID: 7799437
  
  
• Daniel DC and Johnson, EM. (1989) Selective initiation of replication at origin sequences of the rDNA molecule of Physarum polycephalum using synchronous plasmodial extracts. Nucleic Acids Res, 17 (20): 8343-8362. PMC334968

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