Olusola A. Bamishigbin
University of Miami
Junior Year
Chemistry Major
 
Faculty Advisor:
Dr. Michael Frohman, Professor
Department of Molecular Pharmacology
 
Other Research Mentor:
Mary Osisami, Genetics Ph.D. Candidate
 
Visualization of Androgen Receptor Dimerization Using the Bimolecular Fluorescence Complementation Assay
Olusola Bamishigbin(1), Mary Osisami(2), Michael Frohman(2)
 
Bimolecular fluorescence complementation (BiFC) is a method of viewing protein interactions in cells. This microscopy-based assay allows one to view fluorescent signals produced by dimers of fluorescent protein fragments fused to interacting proteins. BiFC was used to study the dimerization of the androgen receptor (AR), an intracellular steroid receptor whose function is prominent in male development. Aberrant AR signaling has been implicated in the initial development of prostate cancer, and is contributory to the progression of Androgen-independent prostate cancer (AIPC). Little is known about the pathways that lead to androgen-independent AR activation and, thus, AIPC. Since AR activation leads to the formation of AR homodimer complexes, we propose that AR signaling activation can be monitored in vitro by measuring AR dimerization using the BiFC assay. AR activation will be monitored by viewing nuclear fluorescent signals produced by dimerized constructs of N- and C-terminal Venus fragments attached to AR. The findings of the study will indicate whether BiFC is an acceptable method of observing AR dimerization in living cells.
 
(1)University of Miami, Miami, FL, USA
(2)Stony Brook University, Stony Brook, NY, USA

Terrin Andrew Celestin
University of Maryland
Baltimore County
Sophomore Year
Computer Engineering Major
 
Faculty Advisor:
Dr. Mikhail Gouzman, Instructional Specialist
Department of Electrical and Computer Engineering
 
A BASIC Stamp microcontroller that reads fluorescent light for skin cancer detection
Terrin Celestin(1), Mikhail Gouzman(2)
 
Many people in countries near the equator suffer from skin cancer and cannot see the early signs of the cancer because of the tone of their skin. When skin cancer cells are dyed with a certain solution, they produce fluorescent light to distinguish the cancer cells from healthy cells. A suntracker was modified to read fluorescent light from skin cancer cells. The microcontroller will move in the direction that sends the most light balancing the amount of light received by each light to frequency converter. The lcd screen attached to the microcontroller displays the correct period of the light that each converter reads. This microcontroller will read all light frequencies, but moves only when a particular frequency is received. This inexpensive device will rotate in the direction towards the fluorescent light radiated from the cancer cells. The skin cancer detector will be used as a diagnostic tool for physicians dispersed around countries near the equator to see whether a patient has skin cancer or not.
 
(1)University of Maryland Baltimore County, Baltimore, MD, USA
(2)Stony Brook University, Stony Brook, NY, USA

Alysia Foster
Delaware State University
Junior Year
Psychology Major
 
Faculty Advisor:
Dr. Suparna Rajaram, Professor
Department of Psychology (Biopsychology)
 
Other Research Mentor:
Helena Blumen, Psychology Ph.D. Candidate
 
Towards Localizing the Nature of Conceptual Deficits in Medial Temporal Lobe Amnesia: An Empirical Model of the Free Association Task
Alysia Foster(1) , Helena M. Blumen(2), and Suparna Rajaram(2)
 
Unlike explicit memory (conscious recollection of previous experience), implicit memory provides indirect access to previous experience without involving conscious recollection and is measured in terms of priming (the difference in performance to studied and nonstudied information). Implicit memory is a unique memory function in the sense that it is typically preserved in amnesia. The general goal of this research was to develop a model for examining conceptual priming in memory-intact and amnesic individuals. Conceptual priming tasks such as free association benefit from the conceptual (rather than the perceptual) relationship between study and test. Previous studies suggest that free association performance is intact in amnesia yet, a generation effect (better memory for self-generated information compared to information that has been read) is not observed with this task in memory-intact individuals. The specific goal of this research was to determine if the type of relational processes engaged by generation cues at study (categorical or associative), the strength of the relationship between target and cues at test (weak or strong) - or both - are important for observing generation effects with the free association task in memory-intact individuals. At study, participants read and generated target words paired with categories and associates. At test, participants provided the first word that came to mind given a strong or weak associative cue. We predicted that a generation effect would be observed - or would be greater - when there was a match between the relational processes engaged by the generation cue at study and the test (associative-associative) and when weak associates were used at test.
 
(1)Delaware State University, Dover, DE, USA
(2)Stony Brook University, Stony Brook, NY, USA

Cindy V. Leiton
University of New Haven
Junior Year
Biochemistry Major
 
Faculty Advisor:
Dr. Holly Colognato, Assistant Professor
Department of Molecular Pharmacology
 
Other Research Mentor:
Iva Tzvetanova, Pharmacology Ph.D. Candidate
 
Phosphatase roles in regulation of fyn tyrosine kinase activity are required for oligodendrocyte differentiation
Cindy V. Leiton(1), Iva Tzvetanova(2), and Holly Colognato(2)
 
Fyn activation is required for myelination to occur in oligodendrocytes. Deactivation of Fyn is mediated by phosphorylation at the tyrosine 529 (Y529) by the kinase Csk. Two distinct events are required for full Fyn activation: Fyn activation could occur through two proposed mechanisms: Y418 autophosphorylation, or Y529 dephosphorylation by the tyrosine phosphatases, SHP-1 or PTPB1. The present study examined whether dephostatin, a protein tyrosine phosphatase (PTP) inhibitor of SHP-1 and PTPB1, alters Fyn phosphorylation at the Y529 and Y418 sites. In addition, the proposed phosphatases' role was tested in the presence of known regulators of the myelination process, extracellular matrix components (laminin and fibronectin), and a growth factor, neuregulin. Increasing concentration doses of dephostatin caused a decrease in myelination, as indicated by MBP expression, and an increase of phosphorylation at the Fyn Y529 site. We also observed that dephostatin modulated levels of phosphorylated AKT, a kinase that controls oligodendrocyte survival. In agreement, a live-dead assay showed that cell survival was reduced in the presence of dephostatin. Finally, we found that laminin amplified the inhibition of MBP expression effect of dephostatin. Phosphatase activity in the Fyn pathway is key in understanding the activation of Fyn and how it could be further modulated to stimulate myelination in diseases such as Multiple Sclerosis where myelin is destroyed.
 
(1)University of New Haven, New Haven, CT, USA
(2)Stony Brook University, Stony Brook, NY, USA

Afoma Ndubuisi
Binghamton University
Junior Year
Biochemistry Major
 
Faculty Advisor:
Dr. Michael Frohman, Professor
Department of Molecular Pharmacology
 
Other Research Mentor:
Dr. Yelena Altshuller, Sr. Research Specialist
Mary Osisami, Genetics Ph.D. Candidate
 
Analysis of the homodimerization of Mitofusin-2 during normal Mitochondrial activity using Bimolecular Fluorescence Complementation
Ashley Dapremont(1), Yelena Altshuller(2), Mary Osisami(2), and Michael Frohman(2)
 
Mitochondria are complex organelles that actively divide and fuse. Their shape is affected by several factors including the developmental stage of the cell. Mitochondrial fusion and fission are activities required to maintain normal mitochondrial functions such as energy production and movement across the cytoplasm. Mitochondria must maintain a balance between fusion and fission or they may become either highly fragmented or extremely elongated. Mutations in the active domains of mitofusin-2 (mfn-2), a fundamental protein for mitochondrial fusion, have been shown to lead to mitochondrial fragmentation and, subsequently, a loss of normal shape and function. Studies have shown that during mouse embryonic development, deletion of mfn-2 results in embryonic death. In humans, mutated mfn-2 leads to two types of neurodegenerative diseases, dominant optic atrophy and Charcot-Marie-Tooth neuropathy. Despite this knowledge, the mechanism of action of mfn-2 is not well known. The hypothesis of this study is that mfn-2 homodimerizes in its mechanism of achieving mitochondrial fusion. This was analyzed using Bimolecular Fluorescence Complementation, a technique used to visualize protein interactions.
 
(1)Binhamton University, Binghamton, NY, USA
(2)Stony Brook University, Stony Brook, NY, USA

Jade Reid
Syracuse University
Junior Year
Biology Major
 
Faculty Advisor:
Dr. Michael Hayman, Professor
Dept of Molecular Genetics & Microbiology
 
Other Research Mentor:
Dr. Irene Ischenko, Sr. Research Specialist
Kimberly Gottfredsen, Genetics Ph.D.
 
Gab Proteins and RON-mediated Signaling
Jade Reid(1), Kimberly Gottfredsen(2), Irene Ischenko(2), Michael Hayman(2)
 
RON, (recepteur d' origine nantais), is a receptor tyrosine kinase that can cause the increased growth, invasion and metastasis of tumors when over expressed in epithelial cells. When phosphorylated by its ligand, the Macrophage-Stimulating Protein, (MSP), RON signals the Gab adaptor proteins, Gab1 and possibly Gab2. These proteins then heighten cellular signaling and, therefore, may contribute to cellular transformation. Gab1 is necessary for cellular processes and when compared to normally functioning breast epithelial cells it is not over expressed in breast cancer carcinomas but Gab2 is over expressed in breast cancer and proliferation. In addition, studies with v-Sea, a RON homolog found in chickens, reveal that Gab 2 influences the transformation of fibroblasts. The current study uses western blotting and immunofluorescence techniques with NIH3T3, MCF10A and Cos1 cell lines to explore how the Gab adaptor proteins contribute to RON-mediated signaling. I hypothesize that Gab2 is the dominating protein, but Gab1 is also necessary to induce the progression of cancer cells. Insight into how Gab1 and/or Gab2, work together to cause the transformation, proliferation, and metastasis of normal cells will provide a potential target in the treatment of breast carcinomas.
 
(1)Syracuse University, Syracuse, NY, USA
(2)Stony Brook University, Stony Brook, NY, USA

Shayla Shorter
University of Maryland
Baltimore County
Sophomore Year
Biology Major
 
Faculty Advisor:
Dr. Gary Zieve, Associate Professor
Department of Pathology
 
Evolution of Lupus Associated B Cell Autoepitopes in the Sm proteins
Shayla Shorter(1), Gary Zieve(2)
 
Systemic Lupus Erythematosus (SLE), is an autoimmune disease characterized by the production of autoantibodies against cellular components and the deposition of immune complexes in tissues. Autoantibodies against Sm proteins are seen in approximately 30% of SLE patients and thus are of great diagnostic value. (1) Sm proteins form a ring of 7 different proteins (B, D1, D2, D3, E, F, and G) and are part of the protein-RNA complex known as small nuclear ribonucleoproteins (snRNPs) that function in pre-mRNA splicing. Studies on the most commonly targeted Sm proteins, SmB, SmD1, and SmD3 demonstrate that symmetrical dimethylation of the arginine in glycine-arginine-glycine (GRG) motifs, located in the C terminus of the proteins that extends outward from the ring domain, plays a critical role in its emergence as a Lupus autoepitope.(2)
 
The Sm proteins are highly conserved throughout the eukaryotes. We sought to study the evolution of the GRG motifs in the Sm proteins and correlate them with the emergence of the modern immune system. Using Bonsai, a program that assists in protein sequence alignment and evolutionary tree building, we identified and numbered the different occurrences of the GRG motifs recognized as a Lupus autoepitope in the Sm B, D1, and D3 proteins. When plotted on an evolutionary tree, we show three GRG motifs appearing in SmB where the vertebrate lineage began and one appearing at the divergence point between proteostomes and deuterostomes. Proteins D1 and D3 show similar results as most motifs appeared before the arrival of vertebrates. These results show that most of the sequences occurred before the development of adaptive immunity and thus autoimmunity-capable immune systems. The conservation of these motifs suggests its importance to the survival of the organisms while its later transformation into an autoepitope suggests a detrimental effect. Studying these motifs on an evolutionary scale helps to develop an understanding of the importance of sequence function and the significance of their role as autoepitopes in lupus.
 
(1) Riemekasten G, Marell J, Trebeljahr G, Klein R, Hausdorf G, Haupl T, Schneider-Mergener J, Burmester GR, Hiepe F.2000 J. Biol Chem. A novel epitope on the C-terminus of SmD1 is recognized by the majority of sera from patients with systemic lupus erythematosus. Jun 2;275(22):17122-9
 
(2) Brahms H, Raymackers J, Union A, de Keyser F, Meheus L, Luhrmann R. 2000. The C-terminal RG dipeptide repeats of the spliceosomal Sm proteins D1 and D3 contain symmetrical dimethylarginines, which form a major B-cell epitope for anti-Sm autoantibodies. The Journal of Biological Chemistry 275-22:17122-17129
 
(1)University of Maryland Baltimore County, Baltimore, MD, USA
(2)Stony Brook University, Stony Brook, NY, USA

Jose Velez Perez
University of Puerto Rico, Cayey
Senior Year
Chemistry Major
 
Faculty Advisor:
Dr. Cindy Lee, Distinguished Professor
Marine Science Research Center
 
Other Research Mentors:
Joan Fabres, Postdoctoral Fellow
Lynn Abramson, Ph.D. Candidate
Zhanfei Liu, Ph.D. Candidate
 
Can pigment fluxes give us information about biogeochemical processes in the Gulf of Lions?
Jose Velez Perez(1), Joan Fabres(2), Lynn Abramson(2), Zhanfei Liu(2) and J. Cindy Lee(2)
 
The carbon cycle describes a series of processes that circulate carbon throughout the Earth's atmosphere, land, and ocean. The ocean is an extremely important component of this cycle. Phytoplankton (small, unicellular algae in the ocean) take up CO2 from the air through the process of photosynthesis, and heterotophic animals and bacteria release CO2 by the process of respiration. Concentrations of different pigments can serve as indicators for particular organisms or processes involved in this cycle. Pigments are colored organic compounds important in absorbing light energy during photosynthesis. All primary producers use chlorophyll a to harness light energy. The zooplankton (small animals and protozoans) and bacteria degrade chlorophyll a to modified forms called pheopigments, which include pyropheophorbide, pheophorbide and pheophytin. The aim of this study is to use measured concentrations of these pigments to better understand biogeochemical processes affecting the sources and fate of organic matter in the Gulf of Lions in the Mediterranean Sea. Possible sources of organic matter to the Gulf of Lions include new organic matter produced in the Gulf itself as well as material transported from the Rhone River, the Sahara Desert, and other areas of the Mediterranean. To determine the relative importance of each of these sources and the fate of this material, samples were taken at the head of six different submarine canyons (270 meters depth) from October 2003 until April 2004 using sediment traps (particle collection devices). We extracted pigments from the samples using acetone and quantified their concentrations by High Performance Liquid Chromatography.
 
Our results show two clearly differentiated periods during the studied time span. The first period, lasting until mid January, is characterized by overall constantly low pigment concentrations. The second one, lasting until the end of the experiment, is by contrast characterized by higher and variable pigment concentration. Pigment concentration time series were compared with series of surface chlorophyll a concentration images obtained by satellite sensors and current speed data obtained by current meters attached to the sediment trap mooring lines. The clear change in pigment concentration from mid January onwards is related to the onset of a phytoplankton bloom over the continental shelf and the upper part of the slope as seen in satellite images. Nevertheless the fluctuations in concentration within the second period do not reflect the higher frequency variations in chlorophyll a concentration in surface waters but the changes on near bottom current intensity. This relation has been interpreted as the result of the enhanced transfer of pigment rich particles accumulated ephemerally on the shelf during increased current episodes. Furthermore, the slightly different evolution of zooplankton derived pigments (pheophorbide and pyropheophorbide) has been tentatively linked to the degradation of chlorophyll a by different zooplankton communities at the beginning and the end of the second period, and, the steady increase of pheophytin concentration towards the end of the second period probably reflects the more bacterially degraded nature of the transferred particles. It is then clear that pigment fluxes and concentrations can definitely provide information on the biogeochemical processes in the Gulf of Lions.
 
(1)University of Puerto Rico, Cayey, Cayey, Puerto Rico
(2)Stony Brook University, Stony Brook, NY, USA

Mabel Rodriguez
Stony Brook University
Freshman Year
Engineering Chemistry Major
 
Faculty Advisor:
Dr. J. Carlos Rojo, Assistant Professor
Department of Materials Science
 
Other Research Mentor:
Dr. Joan Carvajal, Postdoctoral Fellow
Department of Materials Science
 
Synthesis of GaN nanostructures using Chemical Vapor Deposition Assisted by UV Radiation
Mabel Rodriguez(1), Nadia M. Gomez(1), Joan J. Carvajal(1), J. Carlos Rojo(1)
 
Gallium Nitride (GaN) presents unique physical properties, such as a direct band-gap, which can be used in the fabrication of short-wavelength emitters and detectors and high power, high frequency, high temperature electronic devices. We have been able to produce GaN nanostructures through a process based on the direct reaction between Gallium (Ga) and Ammonia at temperatures higher than 800 °C. By using UV- radiation we still expect to produce GaN nanostructures at lower temperatures. To achieve this, the ammonia molecules should be excited by another source to make them more reactive with Ga at lower temperatures. The UV-radiation will excite the ammonia molecules to a higher energy level in which the molecules can resonate destructively, breaking the bonds of the ammonia molecules and inciting the ammonia to react with Ga, hopefully forming GaN nanostructures at lower temperatures. One of the advantages of producing GaN at lower temperatures is that we can introduce other ions in the structure, such as Indium (In), which can induce a reduction in the size of the band-gap of the semiconductor. This may allow us to produce rich- Indium Gallium Nitride (GaInN) structures with a band-gap lying in the green-yellow region of the electromagnetic spectrum. These new alloys may have applications in the generation of pure green and yellow light emitters.
 
(1) Stony Brook University, Stony Brook, NY, USA
 

 
Rose Saint Fleur
Ph.D. Candidate in Applied Math & Statistics
 
SRI Office Liaison

 
Nilsson Holguin
Ph.D. Candidate in Biomedical Engineering
 
Research Methods Instructor

 
Dumaine Williams
Ph.D. Candidate in Molecular Pharmacology
 
Research Methods Instructor

 
Sue Natali
Ph.D. Candidate in Ecology & Evolution
 
Writing Instructor

 
Akua Bonsra
Ph.D. Cnadidate in Molecular Pharmacolog
 
Activities Coordinator

 
Omolola Ojo
Master's Candidate in Applied Math & Statistics
 
Resident Liaison Officer