Courses I teach:
SC111 - Foundations of Chemistry I
SC112 - Foundations of Chemistry II
SC335 - Biochemistry I
SC491/495/496 - 1-3 credit Chemistry Research Project
SC486C - Molecular Virology
My students and I employ various molecular biology, biochemical, and biophysical methods to understand the biochemistry of retroviruses such as HIV-1 and the human endogenous retrovirus type K (HERV-K). Retroviruses have an RNA genome which is converted to DNA and subsequently integrated into the genome of the infected cell. Camouflaging as a host gene, the retroviral genome is then replicated by the host cell’s transcriptional machinery. I am particularly interested in understanding how the newly synthesized, unspliced retroviral RNA genome is exported from the nucleus to the cytoplasm. In HIV-1, this step is carried by the Rev protein which specificially binds to the RRE region on the genomic RNA. This step is essential in retroviral replication and, thus, an ideal target for the development of novel therapeutics.
Human endogenous retroviruses (HERVs) refer to sequences of viral origin that comprise ~8% of our genome. When retroviruses infect germ cells, the integrated viral DNA is passed on in a Mendelian manner; it becomes endogenized. Most of these sequences have accumulated inactivating mutations but some, such as HERV-K, are actively expressed. HERV-K and HIV-1 exhibit some similarities such as the use of homologous protein and RNA pairs (Rev/RRE and Rec/RcRE) to export unspliced genomic RNA. I am interested in characterizing the Rec protein and understanding the biochemistry of the HERV-K Rec/RcRE interactions.
- Mikhalkevich N, O’Carroll IP, Tkavc R, Lund K, Sukumar G; Dalgard CL, Johnson KR, Li W, Wang T, Nath A and Iordanskiy S. 2021. Macrophage response to gamma radiation is mediated via human endogenous retrovirus-K expression. PLOS Pathogens. 17(2):e1009305
- O’Carroll IP&, Fan L, Kroupa T, McShane EK*, Theodore C*, Yates EA, Kondrup K*, Ding J, Martin TS*, Rein A, and Wang Y-X. 2020. Structural mimicry drives HIV Rev-mediated HERV-K expression. Journal of Molecular Biology. 432(24):166711. *Undergraduate student, &Corresponding author.
- O’Carroll IP, Buck M, Durkin P, and W.S. Farrell. 2020. With anchors aweigh, synchronous instruction is preferred by Naval Academy instructors in small undergraduate chemistry courses. Journal of Chemical Education. 97 (9), 2383-2388.
- O’Carroll IP, Thappeta Y, Fan L, Valdez-Ramirez E, Smith S*, Wang Y-X, and Rein A. 2017. Contributions of individual domains to function of the HIV-1 Rev response element. Journal of Virology. Vol. 91, Issue 21, e00746-17. This article was one of Editor’s 4 picks. *Undergraduate student
- O’Carroll IP and Rein A. 2015. Viral nucleic acids. Online Encyclopedia of Cell Biology.
- Fang X*, Wang J*, O’Carroll IP*, Mitchell M, Zuo X, Wang Y, Yu P, Rausch JW, Dyba MA, Kjems J, Schwieters CD, Seifert S, Winans R, Watts N, Stahl S, Wingfield P, Byrd RA, LeGrice S, Rein A, Wang Y-X. 2013. A unique topological structure of the HIV-1 Rev response element. Cell, 155(3):594-605. *Equal contribution by author.
- O’Carroll IP, Crist RM, Mirro J, Harvin D, Soheilian F, Kamata A, Nagashima K, and Rein A. 2013. Elements in HIV-1 Gag contributing to virus particle assembly. Virus Research. 171:341-345.
- O’Carroll IP, Crist RM, Mirro J, Harvin D, Soheilian F, Kamata A, Nagashima K, and Rein A. 2012. Functional Redundancy in HIV-1 Assembly. Journal of Virology. 86(23):12991-6.
- O’Carroll IP and Dos Santos PC. 2011. Genomic analysis of nitrogen fixation. Methods Mol. Biol. 766:49-65.
- Setubal JC, dos Santos P, Goldman BS, Ertesvåg H, Espin G, Rubio LM, Valla S, Almeida NF, Balasubramanian D, Cromes L, Curatti L, Du Z, Godsy E, Goodner B, Hellner-Burris K, Hernandez JA, Houmiel K, Imperial J, Kennedy C, Larson TJ, Latreille P, Ligon LS, Lu J, Maerk M, Miller NM, Norton S, O'Carroll IP, Paulsen I, Raulfs EC, Roemer R, Rosser J, Segura D, Slater S, Stricklin SL, Studholme DJ, Sun J, Viana CJ, Wallin E, Wang B, Wheeler C, Zhu H, Dean DR, Dixon R, and Wood D. 2009. Genome sequence of Azotobacter vinelandii, an obligate aerobe specialized to support diverse anaerobic metabolic processes. J. Bacteriol. 191(14):4534-45.
- Raulfs EC*, O’Carroll IP*, Dos Santos PC, Unciuleac M-C, and Dean DR. In vivo iron-sulfur cluster formation. 2008. Natl. Acad. Sci. USA. 105(25):8591-8596. *Equal contribution by authors.
- Bandyopadhyay S, Naik SG, O’Carroll IP, Huynh B-H, Dean DR, Johnson MK, and Dos Santos PC. 2008. A proposed role for the Azotobacter vinelandii NfuA protein as an intermediate iron-sulfur cluster carrier. Biol. Chem. 283(20):14092-14099.
- Smith MB, Ruby S, Horouzhenko S, Buckingham B, Richardson J, Puleri I, Potts E, Jorgensen WL, Arnold E, Zhang W, Hughes SH, Michejda CJ, and Smith RH Jr. 2003. HIV-1 reverse transcriptase variants: molecular modeling of Y181C, V106A, L100I, and K103N mutations with non-nucleoside inhibitors using Monte Carlo simulations in combination with a linear response method. Drug Design Discov. 18(4):151-63.
Emily Liu ('24) is studying protein-RNA interactions using electrophoretic mobility shift assays.
Erin McShane (’19) is loading RNA samples on a native gel in the cold room to purify the human endogenous retrovirus type K (HERVK) nuclear export signal, RcRE. Her purified sample was sent to the synchrontron at the Argonne National Laboratory to solve the small angle X-ray scattering structure of the RcRE RNA. Erin was a Garrigues scholarship recipient during 2018-2019 academic year. She is currently a 2nd-year medical student at Stanford School of Medicine.
Christophe Theodore (’20) and 1/C Tyler Martin (’20) analyzing an SDS-PAGE gel. They are purifying the HIV-1 Rev protein and the Human Endogenous Retrovirus Type K (HERV-K) Rec protein (an oncoprotein) in order to understand the mechanism of HERV-K expression. Christophe is currently in flight school and Tyler is a 1st-year student at the USUHS School of Medicine.
Ben Phelps (’20) is transfecting a laboratory human cell line with plasmids to test the potential for human endogenous retrovirus type K (HERVK) antisense transcription activity. He is pictured at our collaborator’s, Sergey Iordanskiy’s, lab at USUHS. He is currently a 1st-year medical student at the USUHS School of Medicine
Ina Puleri O'Carroll, Ph.D.
B.A. Biochemistry and Chemistry (Honors, Magna cum laude), McDaniel College
Ph.D. Biochemistry, Virginia Tech
Postdoctoral Training: National Institutes of Health