Biography

Education

M.Div. (Master of Divinity), Howard University School of Divinity (Washington, DC)

Postdoctoral Fellow (Staff Researcher), Roche Institute of Molecular Biology, Hoffman-LaRoche, Inc., (Nutley, NJ)

Ph.D., Cell and Molecular Biology, University of Missouri (Columbia, MO)

B.S., Biology, South Carolina State University (Orangeburg, SC)

Courses Currently Teaching

Dental Biochemistry

M1 (Molecules and Cells Unit 1A, TBL platforms)

General (Graduate) Biochemistry

General (Graduate) Biochemistry Laboratory (Course Coodinator)

Orientation to Research (Course Coordinator)

Special Topics in Biochemistry (Research)

Research for Ph.D. (Graduate Thesis Advisor)

Research Interests/Areas of Expertise

Research Focus 1:

Hereditary, Genomic, Behavioral, and Transcriptional Analysis of Tshrhyt Mutant Parkinsonian Mouse

Synopsis of Project: Little is understood about the genetics of Parkinson’s disease (PD), however recent progress within molecular genetics has identified several genes, such as leucine-rich repeat kinase 2 (LRRK2), α-synuclein and parkin which are linked to PD. This project will focus on strategies aimed to understand the genetic factors that contribute to dopaminergic degeneration in the substantia nigra and ventral tegmental areas.  Thyroid stimulating hormone receptor (Tshr) mutant mice harbor a point mutation within the transmembrane domain IV of the receptor. A subset of the Tshr mutant mice that are homozygous (hyt/hyt), demonstrate spontaneous circling behavior that is accompanied by dopaminergic loss within the SN. The assessment of cellular and molecular differences between sibling littermates can be valuable in the determination of the genetic predisposition to PD. The Tshr-hyt mutant, when subjected to pedigree analysis, assessment of dopaminergic-acetylcholinesterase content, RT-PCR and DNA methylation studies will help to elucidate the molecular basis of Parkinsonism-like symptoms. These experiments may reveal specific genetic heritability factors that are adjunct to homozygous circling behavior and dopaminergic degeneration in the SN. This project will help improve the understanding of neurodegeneration in the mammalian central nervous system and contribute to the improvement of drug development, and therapeutic interventions.

Research Focus 2:

Development of novel (amyloid precursor protein) APP-hypothyroid mouse models underlying CNS amyloidosis and Alzheimer’s disease pathology. The etiology of Alzheimer’s disease (AD) is unknown and elucidating the molecular and biochemical pathway underlying AD is an important subject of investigation. The formation of amyloid beta (Ab) plaques in the brain cortex is linked to the cognitive dysfunction of AD. Research in AD is bolstered by the development of transgenic “humanized” mouse models that resemble the pathogenesis of the accumulation Ab deposits in the CNS. Recent findings suggest that clinical hypothyroidism, and the use of anti-thyroid drugs in rodents is associated with progression of AD signatures, such as increased formation of amyloid plaques (insoluble deposits) and memory impairment. Our research focuses on the development of hybrid Parkinsonism-Alzheimer's mouse models (Tshr-hyt/TgAPP) with shared phenotypes of amyloid plaque formation and hypothyroidism to better understand linkages between these variables in AD.

Research Focus 3:

Molecular Genetics of the Eukaryotic Model Organism, Dictyostelium discoideum.

Dictyostelium discoideum possesses several unique features that make it an excellent model organism for scientific investigations. The Dictyostelium genome is relatively simple, consisting of approximately 12 million base pairs and 12,500 protein-coding genes, facilitating genetic manipulation and functional studies. Importantly, its genome harbors orthologs to many human genes that are associated with cellular processes underlying disease. D. discoideum exhibits a remarkable ability to switch between solitary amoeboid growth and multicellular development, making it an ideal system for investigating cellular differentiation and cell signaling pathways. This development process, which shares similarities with the formation of tissues and organs in higher organisms, has provided valuable insights into mechanisms of cell 4 4 differentiation, pattern formation, and cell-cell communication. Cellular molecular genetic analyses of glutathione S transferase (GST) enzymes; major focus is to characterize the enzymatic and non-enzymatic roles of GST enzymes in the regulation of cell proliferation, development, differentiation, and morphogenesis within the organism. Non-enzymatic roles and modification of glutathione S-transferase, in addition to their enzymatic activity, GSTs perform various non-enzymatic roles, highlighting their versatility and functional diversity. Our laboratory investigates enzymatic and non-enzymatic functions and modifications of D. discoideum that include:

A) Ligand Binding and Transport: Ligand binding capacity of GSTs extends their role beyond detoxification and suggests their involvement in cellular lipid metabolism and transport processes.

B) Protein-Protein Interactions: Mammalian eukaryotic GSTs interact with numerous proteins, serving as scaffolds for the assembly of multiprotein complexes. These interactions may regulate signaling pathways, protein degradation, and transcriptional regulation. We investigate the potential of D. discoideum GSTs to bind and modulate the activity of mitogen-activated protein kinases (MAPKs) and other factors that influence cell survival, proliferation, and differentiation.

C) Phosphorylation of GST: The phosphorylation of mammalian GSTs is another post-translational modification that has emerged as an additional mechanism to modulate their enzymatic activity and cellular signaling.  These signaling pathways can regulate diverse cellular processes such as cell growth, differentiation, apoptosis, and response to environmental stress. Our laboratory aims to identify specific kinases involved in D.  discoideum GST phosphorylation, the functional consequences of phosphorylation at different molecular sites, and the broader implications of GST phosphorylation in cellular signaling and disease processes.

Systems/Techniques/Expertise

anatomy and histology; immunocytochemistry; microtomy/ultramicrotomy; cryotomy; gene library construction and screening; gene cloning; restriction mapping; generation and cloning of PCR products; expression vector cloning; bacterial transformation; DNA/RNA isolation; Northern, Southern analysis; DNA/RNA hybridization; in situ hybridization; autoradiography; isolation of mitochondrial DNA; in vitro translation of mitochondrial proteins; isolation of microsomes; cytoplasmic/nuclear protein isolation and electrophoresis; ELISA; Western blotting; column and affinity chromatography; biochemistry and enzymology of cytochrome P450; thin-layer chromatography; in vitro cell culture techniques; transgenic technology; animal surgical techniques; light/dark field microscopy; spectrophotometry; microphotography, statistical image analysis; next generation sequence analysis/transcriptome profiling.

Professional Associations

Society for Neuroscience

Association for Chemoreception Sciences (AChemS)

Ordained Clergy, American Baptist Churches, USA