Biochemistry, Biophysics, and Structural Biology Commons^™

Evaluating The Interaction Between The Human Melanocortin-2 Receptor And The Accessory Protein, Mrap1: Chimeric Receptor And Alanine Substitution Studies On Transmembrane Domain 4, Extracellular Loop 2, And Transmembrane Domain 5, Perry Victoria Davis

Electronic Theses and Dissertations

The melanocortin-2 receptor (MC2R) is the most complex due to its trafficking and ligand selectivity requirements for proper activation. The MC2R requires the melanocortin receptor accessory protein-1 (MRAP1) for proper trafficking and activation of the receptor by the melanocortin hormone, ACTH. MRAP1 is a single transmembrane-spanning domain protein that creates a homodimer with another MRAP1 protein. Furthermore, MRAP2 creates a heterodimer with the MC2R. Previous studies have shown that the MRAP1 protein contains an activation motif required for activation of MC2R and this activation motif located on the extracellular space side of the plasma membrane of the cell. The objective …

Studies Of Norspermidine Uptake In Drosophila Suggest The Existence Of Multiple Polyamine Transport Pathways, Michael Dieffenbach

Honors Undergraduate Theses

Polyamines are a class of essential nutrients involved in many basic cellular processes such as gene expression, cell proliferation, and apoptosis. Without polyamines, cell growth is delayed or halted. Cancerous cells require an abundance of polyamines through a combination of synthesis and transport from the extracellular environment. An FDA-approved drug, D,L-α-difluoromethylornithine (DFMO), blocks polyamine synthesis but is ineffective at inhibiting cell growth due to polyamine transport. Thus, there is a need to develop drugs that inhibit polyamine transport to use in combination with DFMO. Surprisingly, little is known about the polyamine transport system in humans and other eukaryotes. Understanding the …

Selective Inhibition Of Ctcf Binding By Ias Directs Tet-Mediated Reprogramming Of 5-Hydroxymethylation Patterns In Ias-Transformed Cells, Matthew Rea, Tyler Gripshover, Yvonne N. Fondufe-Mittendorf

Molecular and Cellular Biochemistry Faculty Publications

Methylation at cytosine (5mC) is a fundamental epigenetic DNA modification recently associated with iAs-mediated carcinogenesis. In contrast, the role of 5-hydroxymethylcytosine (5hmC), the oxidation product of 5mC in iAs-mediated carcinogenesis is unknown. Here we assess the hydroxymethylome in iAs-transformed cells, showing that dynamic modulation of hydroxymethylated DNA is associated with specific transcriptional networks. Moreover, this pathologic iAs-mediated carcinogenesis is characterized by a shift toward a higher hydroxymethylation pattern genome-wide. At specific promoters, hydroxymethylation correlated with increased gene expression. Furthermore, this increase in hydroxymethylation occurs concurrently with an upregulation of ten-eleven translocation (TET) enzymes that oxidize 5-methylcytosine (5mC) in DNA. To …

Carbohydrate-Based Inducers Of Cellular Stress For Targeting Cancer Cell Metabolism, Fidelis Ndombera

Wayne State University Dissertations

ABSTRACT

CARBOHYDRATE-BASED INDUCERS OF CELLULAR STRESS FOR TARGETING CANCER CELL METABOLISM

by

FIDELIS TOLOYI NDOMBERA

May 2018

Advisor: Dr. Young-Hoon Ahn

Major: Chemistry (Biochemistry)

Degree: Doctor of Philosophy

Metabolic reprogramming and redox control of cancer cells is vital for their proliferation, but also provides selective strategies for treating cancer. Increased generation of reactive oxygen species (ROS) and an intricate control of redox status in cancer cells relative to normal cells provide a basis for designing ROS-inducing anticancer agents. In my work, I designed, synthesized and evaluated carbohydrate-based small molecules for ROS-generation, cytotoxicity and redox signaling and stress response. Our data …

Asymmetric Patterns Of Small Molecule Transport After Nanosecond And Microsecond Electropermeabilization, Esin B. Sözer, C. Florencia Pocetti, P. Thomas Vernier

Bioelectrics Publications

Imaging of fluorescent small molecule transport into electropermeabilized cells reveals polarized patterns of entry, which must reflect in some way the mechanisms of the migration of these molecules across the compromised membrane barrier. In some reports, transport occurs primarily across the areas of the membrane nearest the positive electrode (anode), but in others cathode-facing entry dominates. Here we compare YO-PRO-1, propidium, and calcein uptake into U-937 cells after nanosecond (6 ns) and microsecond (220 µs) electric pulse exposures. Each of the three dyes exhibits a different pattern. Calcein shows no preference for anode- or cathode-facing entry that is detectable with …

Expression And Function Of Nuclear Receptor Coactivator 4 Isoforms In Transformed Endometriotic And Malignant Ovarian Cells, Stephanie Rockfield, Idhaliz Flores, Meera Nanjundan

Molecular Biosciences Faculty Publications

Iron is proposed to contribute to the transition from endometriosis to specific subtypes of ovarian cancers (OVCAs). Regulation of intracellular iron occurs via a ferritinophagic process involving NCOA4 (Nuclear Receptor Coactivator 4), represented by two major isoforms (NCOA4α and NCOA4β), whose contribution to ovarian cancer biology remains uninvestigated. We thus generated transformed endometriotic cells (via HRAS^V12A, c-MYC^T58A, and p53 inactivation) whose migratory potential was increased in response to conditioned media from senescent endometriotic cells. We identified elevated NCOA4 mRNA in transformed endometriotic cells (relative to non-transformed). Knockdown of NCOA4 increased ferritin heavy chain (FTH1) and p21 …

Mbd2-Cp2c Loop Drives Adult-Type Globin Gene Expression And Definitive Erythropoiesis, Min Young Kim, Ji Sook Kim, Seung Han Son, Chang Su Lim, Hea Young Eum, Dae Hyun Ha, Mi Ae Park, Eun Jung Baek, Buom-Yong Ryu, Ho Chul Kang, Vladimir N. Uversky, Chul Geun Kim

Molecular Biosciences Faculty Publications

During hematopoiesis, red blood cells originate from the hematopoietic stem cell reservoir. Although the regulation of erythropoiesis and globin expression has been intensively investigated, the underlining mechanisms are not fully understood, including the interplay between transcription factors and epigenetic factors. Here, we uncover that the Mbd2-free NuRD chromatin remodeling complex potentiates erythroid differentiation of proerythroblasts via managing functions of the CP2c complexes. We found that both Mbd2 and Mbd3 expression is downregulated during differentiation of MEL cells in vitro and in normal erythropoiesis in mouse bone marrow, and Mbd2 downregulation is crucial for erythropoiesis. In uninduced MEL cells, the Mbd2-NuRD …

Yeast Lifespan Variation Correlates With Cell Growth And Sir2 Expression, Jessica T. Smith, Jill W. White, Huzefa Dungrawala, Hui Hua, Brandt L. Schneider

Molecular Biosciences Faculty Publications

Isogenic wild type yeast cells raised in controlled environments display a significant range of lifespan variation. Recent microfluidic studies suggest that differential growth or gene expression patterns may explain some of the heterogeneity of aging assays. Herein, we sought to complement this work by similarly examining a large set of replicative lifespan data from traditional plate assays. In so doing, we reproduced the finding that short-lived cells tend to arrest at senescence with a budded morphology. Further, we found that wild type cells born unusually small did not have an extended lifespan. However, large birth size and/or high inter-generational growth …

Radx Modulates Rad51 Activity To Control Replication Fork Protection, Kamakoti P. Bhat, Archana Krishnamoorthy, Huzefa Dungrawala, Edwige B. Garcin, Mauro Modesti, David Cortez

Molecular Biosciences Faculty Publications

RAD51 promotes homologous recombination repair (HR) of double-strand breaks and acts during DNA replication to facilitate fork reversal and protect nascent DNA strands from nuclease digestion. Several additional HR proteins regulate fork protection by promoting RAD51 filament formation. Here, we show that RADX modulates stalled fork protection by antagonizing RAD51. Consequently, silencing RADX restores fork protection in cells deficient for BRCA1, BRCA2, FANCA, FANCD2, or BOD1L. Inactivating RADX prevents both MRE11- and DNA2-dependent fork degradation. Furthermore, RADX overexpression causes fork degradation that is dependent on these nucleases and fork reversal. The amount of RAD51 determines the fate of stalled replication …

Septal Secretion Of Protein A In Staphylococcus Aureus Requires Seca And Lipoteichoic Acid Synthesis, Wenqi Yu, Dominique Missiakas, Olaf Schneewind

Molecular Biosciences Faculty Publications

Surface proteins of Staphylococcus aureus are secreted across septal membranes for assembly into the bacterial cross-wall. This localized secretion requires the YSIRK/GXXS motif signal peptide, however the mechanisms supporting precursor trafficking are not known. We show here that the signal peptide of staphylococcal protein A (SpA) is cleaved at the YSIRK/GXXS motif. A SpA signal peptide mutant defective for YSIRK/GXXS cleavage is also impaired for septal secretion and co-purifies with SecA, SecDF and LtaS. SecA depletion blocks precursor targeting to septal membranes, whereas deletion of secDF diminishes SpA secretion into the cross-wall. Depletion of LtaS blocks lipoteichoic acid synthesis and …

Functional Characterization Of Scaffold Protein Shoc2, Hyein Jang

Theses and Dissertations--Molecular and Cellular Biochemistry

Signaling scaffolds are critical for the correct spatial organization of enzymes within the ERK1/2 signaling pathway and proper transmission of intracellular information. However, mechanisms that control molecular dynamics within scaffolding complexes, as well as biological activities regulated by the specific assemblies, remain unclear.

The scaffold protein Shoc2 is critical for transmission of the ERK1/2 pathway signals. Shoc2 accelerates ERK1/2 signaling by integrating Ras and RAF-1 enzymes into a multi-protein complex. Germ-line mutations in shoc2 cause Noonan-like RASopathy, a disorder with a wide spectrum of developmental deficiencies. However, the physiological role of Shoc2, the nature of ERK1/2 signals transduced through this …

Optimisation Of Ion Exchange Chromatography Purification Protocols For A Staphylococcal Peptidoglycan Degrading Hydrolase Enzyme, Fiona Maher

Theses

Bacteriophage (phage) are the most abundant biological entities on earth and were first discovered by d’Herelle in 1917. They are found wherever their hosts live and, like all viruses they do not have the ability to make their own protein. Therefore, in order to reproduce, phage must invade and infect bacterial cells. This project focused on the optimisation of Ion Exchange Chromatography purification protocols for a staphylococcal peptidoglycan degrading hydrolase enzyme (CHAPk). The project objective was to obtain the greatest yield of enzyme from the growth of the E.coU XL 1-Blue expression system into which the vector pQE60 was previously …

Wild-Type P53 Enhances Endothelial Barrier Function By Mediating Rac1 Signalling And Rhoa Inhibition, Nektarios Barabutis, Christiana Dimitropoulou, Betsy Gregory, John D. Catravas

Bioelectrics Publications

Inflammation is the major cause of endothelial barrier hyper-permeability, associated with acute lung injury and acute respiratory distress syndrome. This study reports that p53 "orchestrates" the defence of vascular endothelium against LPS, by mediating the opposing actions of Rac1 and RhoA in pulmonary tissues. Human lung microvascular endothelial cells treated with HSP90 inhibitors activated both Rac1- and P21-activated kinase, which is an essential element of vascular barrier function. 17AAG increased the phosphorylation of both LIMK and cofilin, in contrast to LPS which counteracted those effects. Mouse lung microvascular endothelial cells exposed to LPS exhibited decreased expression of phospho-cofilin. 17AAG treatment …

Cold Atmospheric Plasma As A Potential Tool For Multiple Myeloma Treatment, Dehui Xu, Yujing Xu, Qingjie Cui, Dingxin Liu, Zhijie Liu, Xiaohua Wang, Yanjie Yang, Niaojuan Feng, Rong Liang, Hailan Chen, Kai Ye, Michael G. Kong

Bioelectrics Publications

Multiple myeloma (MM) is a fatal and incurable hematological malignancy thus new therapy need to be developed. Cold atmospheric plasma, a new technology that could generate various active species, could efficiently induce various tumor cells apoptosis. More details about the interaction of plasma and tumor cells need to be addressed before the application of gas plasma in clinical cancer treatment. In this study, we demonstrate that He+O₂ plasma could efficiently induce myeloma cell apoptosis through the activation of CD95 and downstream caspase cascades. Extracellular and intracellular reactive oxygen species (ROS) accumulation is essential for CD95-mediated cell apoptosis in response …

Efficacy Of Oral Administration Of Sodium Iodide To Prevent Bovine Respiratory Disease Complex, B. M. Shoemake, B. L. Vander Ley, B. W. Newcomer, M. C. Heller

School of Veterinary and Biomedical Sciences: Faculty Publications

Background: The prevention of bovine respiratory disease complex (BRD) in beef cattle is important to maintaining health and productivity of calves in feeding operations.

Objective: Determine whether BRD bacterial and viral pathogens are susceptible to the lactoperoxidase/hydrogen peroxide/ iodide (LPO/H₂O₂/I^-) system in vitro and to determine whether the oral administration of sodium iodide (NaI) could achieve sufficient concentrations of iodine (I) in the respiratory secretions of weaned beef calves to inactivate these pathogens in vivo.

Animals: Sixteen weaned, apparently healthy, commercial beef calves from the University of Missouri, College of Veterinary Medicine teaching herd. …

Investigating Phosphorylation Patterns And Their Effect On The Activity Of Transcription Factor Taabf1 In Imbibing Cereal Grains, Grace Uwase

Honors Theses

The wheat transcription factor TaABF1 plays an important role in hormone-mediated regulation of seed dormancy and germination of cereal grains. Evidence shows that TaABF1 activity is regulated by phosphorylation, and previous work in our lab showed that when serine residues in its conserved regions; S36, S37, S113, S115 were altered to phosphomimetic aspartate, the 4xD TaABF1 mutant had increased activity as a transcription factor. However, when only S113 was altered, TaABF1’s activity was greatly reduced. The work presented here explored whether the S36D/S37D/S115D mutant would have stronger activity than the 4xD mutant. Using the particle bombardment technique to introduce the …

Zebrafish Model Of Mll-Rearranged Acute Myeloid Leukemia, Alex J. Belt

Theses and Dissertations

Acute myeloid leukemia (AML) is the second most common type of leukemia and accounts for 80% of adult acute leukemia cases and is characterized by the accumulation of poorly or undifferentiated myeloid blast cells. Standard treatment includes chemotherapy, which if unsuccessful, is followed by more rigorous chemotherapy as well as stem cell transplantation. Considering most patients are over the age of 45, these more rigorous therapies are not always possible, and as such, new therapies must be developed. Furthermore, AML patients harboring a chromosomal rearrangement involving Multiple Lineage Leukemia (MLL) that results in the expression of an MLL fusion protein …

Coordination Of Different Ligands To Copper(Ii) And Cobalt(Iii) Metal Centers Enhances Zika Virus And Dengue Virus Loads In Both Arthropod Cells And Human Keratinocytes, Shovan Dutta, Michael J. Celestine, Supreet Khanal, Alexis Huddleston, Colin Simms, Jessa Faye Arca, Amlam Mitra, Loree Heller, Piotr Kraj, Michael Ledizet, John F. Anderson, Girish Neelakanta, Alvin A. Holder, Hameeda Sultana

Biological Sciences Faculty Publications

Trace elements such as copper and cobalt have been associated with virus-host interactions. However, studies to show the effect of conjugation of copper(II) or cobalt(III) metal centers to thiosemicarbazone ligand(s) derived from either food additives or mosquito repellent such as 2-acetylethiazole or citral, respectively, on Zika virus (ZIKV) or dengue virus (serotype 2; DENV2) infections have not been explored. In this study, we show that four compounds comprising of thiosemicarbazone ligand derived from 2-acetylethiazole viz., (E)-N-ethyl-2-[1-(thiazol-2-yl)ethylidene]hydrazinecarbothioamide (acetylethTSC) (compound 1), a copper(II) complex with acetylethTSC as a ligand (compound 2), a thiosemicarbazone ligand-derived from citral (compound 3) and a cobalt(III) complex …

Regulated Transcriptional Silencing Promotes Germline Stem Cell Differentiation In Drosophila Melanogaster, Pooja Flora

Legacy Theses & Dissertations (2009 - 2024)

Germ cells are the only cell in an organism that have the capacity to give rise to a new organism and are passed from one generation to the next. Therefore, to maintain this unique ability of totipotency and immortality, germ cells execute specific functions, such as, repression of a somatic program and contour a germ line-specific pre- and post-transcriptional gene regulatory landscape. In many sexually reproducing organisms, germ cells are formed during the earliest stages of embryogenesis and undergoes several stages of development to eventually get encapsulated by the somatic cells of the gonad. Once, in the gonad, the germ …

Chromatin-Signaling Axis Orchestrates The Formation Of Germline Stem Cell Differentiation Niche In Drosophila, Maitreyi Upadhyay

Legacy Theses & Dissertations (2009 - 2024)

Stem cells have the unique capability of self-renewing into stem cells and differentiating into several terminal cell types. Loss of either of these processes can lead to aging, progression towards degenerative diseases and cancers. Insight into how self-renewal and differentiation are regulated will have tremendous therapeutic impact. Drosophila is an excellent model system for stem cell study due to the availability of various mutants, markers and RNAi technology. In order to study stem cell biology, we use female Drosophila gonads, whose stem cell population – the germline stem cells (GSCs) gives rise to gametes.

Retinoic Acid Receptor Isoform-Specific Control Of Mouse Salivary Gland Development And Regeneration, Kara Desantis

Legacy Theses & Dissertations (2009 - 2024)

Controlled expansion and differentiation of progenitor cell populations is essential for organogenesis followed by continued maintenance of the population into and through adulthood. As the K5+ basal cell population is regulated by retinoic acid signaling, we interrogated the contribution of specific RAR isoforms to the regulation of these cells during submandibular salivary gland (SMG) organogenesis and regeneration. Retinoic acid has previously been shown to be involved in the development of the salivary gland, and recently, lack of retinoid signaling has been shown to impact the K5+ population of basal progenitor cells. Since retinoic acid is known to exert stimulatory effects …

Complete Genome Sequence Of Moraxella Bovis Strain Epp-63 (300), An Etiologic Agent Of Infectious Bovine Keratoconjunctivitis, John Dustin Loy, Aaron M. Dickey, Michael L. Clawson

School of Veterinary and Biomedical Sciences: Faculty Publications

We report here the complete closed genome sequence of Moraxella bovis strain Epp-63 (300) (Epp63). This strain was isolated from an infectious bovine keratoconjunctivitis (IBK) case in 1963. Since then, Epp63 has been used extensively for IBK research. Consequently, the genome sequence of Epp63 should help elucidate IBK host-pathogen interactions.

Determination Of The Sivmac Vif-Human Apobec3b Interaction, Oumar Sanogo

All Graduate Theses, Dissertations, and Other Capstone Projects

The APOBEC3 family of enzymes are DNA cytosine deaminases, some of which restrict replication of HIV-­‐1. This viral restriction is caused by deamination of cytosines to uracils in the viral cDNA, resulting in lethal mutation. HIV-­‐1 counteracts this deamination by producing the protein Vif, which targets the restricting APOBEC3 enzymes for proteosomal degradation. Previous studies have demonstrated that HIV-­‐1 Vif mediates degradation of APOBEC3D (A3D), APOBEC3F (A3F), APOBEC3G (A3G), and APOBEC3H (A3H). Other lentiviruses may also encode a Vif protein, however not all Vif proteins can degrade the same APOBEC3 proteins. For example, SIVmac (simian immunodeficiency virus that infects rhesus …

Targeting The Cellular Redox Environment: A Novel Approach For The Treatment Of Hematopoietic Neoplasms, Dustin W. Carroll

Theses and Dissertations--Toxicology and Cancer Biology

Hematopoietic stem cells (HSCs) that function to maintain the hematopoietic compartment through self-renewal and differentiation capacities, as well as their downstream progeny, are susceptible to transformation resulting in the generation of the leukemic stem cell (LSC). Chief in the factors that control HSC regulation and protection of the HSC compartment is the cellular redox environment. Deregulation of the Hematopoietic Stem/Progenitor Cell (HSPC) redox environment results in loss of HSPC function and exhaustion. The characteristic developments of HSPC exhaustion via exposure to redox stress closely mirror phenotypic traits of hematopoietic malignancies, presenting the HSPC/LSC redox environment as a potential therapeutic target. …

Altering Oligomerization Of Epha2 Via Mutations In The Intracellular Domain, Ryan W. Lingerak

Williams Honors College, Honors Research Projects

Eph receptor tyrosine kinases (RTKs) are activated by membrane-bound ligands called ephrins. Eph RTKs are divided into two subclasses, each activated by a specific classes of the ligand ephrin. The overexpression of Eph receptors is correlated to cancer cell metastasis in several different types of cancers. Studies with the EphA2 extracellular domain (ECD) and ephrinA1 ligand have shown that upon binding of ephrin to the receptor, EphA2 undergoes increased oligomerization and activation. This indicates that oligomerization is intimately connected to kinase activity. High resolution crystal structures of the EphA2 ECD have revealed some details of these ligand bound oligomers, as …

Controlling Platelet Secretion To Modulate Hemostasis And Thrombosis, Smita Joshi

Theses and Dissertations--Molecular and Cellular Biochemistry

Upon vascular injury, activated blood platelets fuse their granules to the plasma membrane and release cargo to regulate the vascular microenvironment, a dynamic process central to platelet function in many critical processes including hemostasis, thrombosis, immunity, wound healing, angiogenesis etc. This granule- plasma membrane fusion is mediated by a family of membrane proteins- Soluble N-ethyl maleimide Attachment Receptor Proteins(SNAREs). SNAREs that reside on vesicle (v-SNAREs) /Vesicle-Associated Membrane Proteins(VAMPs) interact with target/t-SNAREs forming a trans-bilayer complex that facilitates granule fusion. Though many components of exocytic machinery are identified, it is still not clear how it could be manipulated to prevent …

Development Of Septic Polysynovitis And Uveitis In Foals Experimentally Infected With Rhodococcus Equi, Laura Huber, Steeve Giguère, Londa J. Berghaus, Amanda Hanafi, Sarah Vitosh-Sillman, Sarah L. Czerwinski

School of Veterinary and Biomedical Sciences: Faculty Publications

Rhodococcus equi is one of the most important causes of disease in foals. Infection is typically characterized by pyogranulomatous pneumonia although extrapulmonary infections occur occasionally. Uveitis and polysynovitis have been reported in foals naturally infected with R. equi and are thought to be the result of an immune-mediated process. However, the pathogenesis of these conditions is poorly understood. The objectives of this study were to document the occurrence of uveitis and polysynovitis after experimental infection with R. equi and to determine if these disorders are the direct result of infection at these sites. Foals between 3 and 4 weeks of …

Alkaline Stabilization Of Manure Slurry Inactivates Porcine Epidemic Diarrhea Virus, Erin E. Stevens, Daniel N. Miller, Bethany A. Brittenham, Sarah J. Vitosh-Sillman, Bruce W. Brodersen, Virginia L. Jin, John D. Loy, Amy M. Schmidt

School of Veterinary and Biomedical Sciences: Faculty Publications

Hydrated lime manure treatment was evaluated to determine porcine epidemic diarrhea virus (PEDV) susceptibility to alkaline stabilization. At pH 10, PEDV decreased (quantitative polymerase chain reaction) and lost infectivity (swine bioassay). Although ammonium decreased above pH 9 (up to 25%), alkaline stabilization managed to control potential infection from manure sources.

Matrix-Assisted Laser Desorption/Ionization Time-Of-Flight Mass Spectrometry Identification Of Moraxella Bovoculi And Moraxella Bovis Isolates From Cattle, Kara Robbins, Aaron M. Dickey, Michael L. Clawson, John Dustin Loy

School of Veterinary and Biomedical Sciences: Faculty Publications

Infectious bovine keratoconjunctivitis (IBK) is an economically significant disease caused by Moraxella bovis. Moraxella bovoculi, although not reported to cause IBK, has been isolated from the eyes of cattle diagnosed with IBK. Identification of M. bovis and M. bovoculi can be performed using biochemical or DNA-based approaches, both of which may be time consuming and inconsistent between laboratories. We conducted a comparative evaluation of M. bovoculi and M. bovis identification using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) with a database provided by Bruker Daltonics (termed the BDAL database), the BDAL database supplemented with spectra generated in …

Circadian Behavioral Responses To Light And Optic Chiasm-Evoked Glutamatergic Epscs In The Suprachiasmatic Nucleus Of Iprgc Conditional Vglut2 Knock-Out Mice, Michael G. Moldavan, Patricia J. Sollars, Michael R. Lasarev, Charles N. Allen, Gary E. Pickard

School of Veterinary and Biomedical Sciences: Faculty Publications

Intrinsically photosensitive retinal ganglion cells (ipRGCs) innervate the hypothalamic suprachiasmatic nucleus (SCN), a circadian oscillator that functions as a biological clock. ipRGCs use vesicular glutamate transporter 2 (vGlut2) to package glutamate into synaptic vesicles and light-evoked resetting of the SCN circadian clock is widely attributed to ipRGC glutamatergic neurotransmission. Pituitary adenylate cyclase-activating polypeptide (PACAP) is also packaged into vesicles in ipRGCs and PACAP may be coreleased with glutamate in the SCN. vGlut2 has been conditionally deleted in ipRGCs in mice [conditional knock-outs (cKOs)] and their aberrant photoentrainment and residual attenuated light responses have been ascribed to ipRGC PACAP release. However, …