Doctor of Philosophy (Ph.D.)
Chemistry
University of Michigan Ann Arbor
2004
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Faculty
Faculty
Dinari Harris, Ph.D.
Assistant Professor
Department/Office
- Chemistry
School/College
- College of Arts & Sciences
Biography
Dinari A. Harris, Ph.D. is an assistant professor in the Department of Chemistry at Howard University in Washington, D.C. He earned a Bachelor of Science sin biochemistry, cum laude, from the University of Maryland Baltimore County and a doctorate in chemistry from the University of Michigan in Ann Arbor. Prior to his appointment at Howard, Harris also completed a rotation in extramural research at the National Heart, Lung, and Blood Institute at the National Institutes of Health, where he focused on implementation and systems science approaches to reduce health disparities.
Harris’s professional work spans research and teaching in chemistry and related biological sciences. At Howard University, he engages students in chemical research and contributes to advancing knowledge in biochemical processes. His prior teaching experience includes courses in general biology, genetics, molecular genetics, recombinant DNA methodology, and forensic science at institutions such as the Catholic University of America and the Foundation for Advanced Education in the Sciences at NIH.
In addition to his academic roles, Harris has participated in national scientific conferences and forums, including organizing think tank discussions on health inequities and contributing to portfolio reviews of health disparities research. Throughout his career, he has integrated research, education and service to broaden understanding of chemistry’s role in addressing complex scientific and societal challenges.
Education & Expertise
Education
Bachelor of Science (B.S.)
Biochemistry
University of Maryland Baltimore County (UMBC)
1999
Academics
Academics
CHEM151: Biochemistry I (undergraduate)
CHEM251: Biochemistry I (graduate)
CHEM151: Organic Chemistry Lab (undergraduate)
Research
Research
Specialty
Biochemistry and cellular biophysics; Cancer progression and metastasis; Fluorescence microscopyAccomplishments
Accomplishments
Visual Sciences Training Grant; 2009-2010
Oncogenesis and Developmental Biology Training Grant; 2008-2009
Damon Runyon Postdoctoral Research Fellowship; 2005-2008
Publications and Presentations
Publications and Presentations
Exosomes released from breast cancer carcinomas stimulate cell movement
Exosomes released from breast cancer carcinomas stimulate cell movement
Here, we study the effect of exosomes on cell migration, an important step in metastasis. We performed cell migration assays, endocytosis assays, and exosome proteomic profiling on exosomes released from three breast cancer cell lines that model progressive stages of metastasis. Results from these experiments suggest: (1) exosomes promote cell migration and (2) the signal is stronger from exosomes isolated from cells with higher metastatic potentials; (3) exosomes are endocytosed at the same rate regardless of the cell type; (4) exosomes released from cells show differential enrichment of proteins with unique protein signatures of both identity and abundance.
Cargo sorting to lysosome-related organelles regulates siRNA-mediated gene silencing
Cargo sorting to lysosome-related organelles regulates siRNA-mediated gene silencing
Mammals lacking BLOC-3 have impaired formation of melanosomes, a type of lysosome-related organelle (LRO), and, in earlier work, we found that a subunit of the BLOC-3 complex inhibits loading of Argonaute (Ago) proteins with small ribonucleic acids (RNAs) in Drosophila melanogaster cells. Small RNAs such as small interfering RNAs (siRNAs) direct Ago proteins to repress the stability of messenger RNA transcripts. In this paper, we show that BLOC-3 is required for biogenesis of Drosophila LROs called pigment granules. Other complexes that sort cargo to pigment LROs also negatively regulate siRNA activity. However, regulation is not obligately linked to biogenesis of LROs but instead to specific cargo-sorting processes. Negative regulation is also not linked to sorting into all LROs but only a specific class of pigment LRO. Thus, regulation of siRNA activity is tied to sorting of specific types of cargo to particular LROs.
The RNAi pathway initiated by Dicer-2 in Drosophila
The RNAi pathway initiated by Dicer-2 in Drosophila
Injection or expression of double-stranded RNA (dsRNA) in Drosophila serves as a trigger that causes cells to specifically cleave homologous mRNA transcripts. Our approach is to identify essential components of the RNA interference (RNAi) mechanism by isolating and characterizing mutations that cause the RNAi response to be abnormal. These studies have thus far led to the identification of seven genetic loci that encode proteins acting at various steps in the RNAi process. We have molecularly identified several of these proteins. Two are members of the Dicer family. Dicer-1 and Dicer-2 are required for short interfering RNA (siRNA)-directed mRNA cleavage by facilitating distinct steps in the assembly of the RNA-induced silencing complex (RISC). AGO2 is a RISC component that both carries out transcript cleavage and facilitates RISC maturation. Other factors appear to function as regulators of RISC assembly rather than as core factors for RNAi.