Genetics and Genomics Commons^™

Ccl3l1 And Hiv/Aids Susceptibility, Thomas J. Urban, Amy C. Weintrob, Jacques Fellay, Sara Colombo, Kevin V. Shianna, Curtis Gumbs, Margalida Rotger, Kimberly Pelak, Kristen K. Dang, Roger Detels, Jeremy J. Martinson, Stephen J. O'Brien, Norman L. Letvin, Andrew J. Mcmichael, Barton F. Haynes, Mary Carrington, Amalio Telenti, Nelson L. Michael, David B. Goldstein

Biology Faculty Articles

No abstract provided.

The Role Of Human Endogenous Retroviruses In Renal Cell Carcinoma, Michele D. Tisdale

Biological Sciences Theses & Dissertations

Human endogenous retroviruses make up approximately 8-9% of the human genome. A number of expressed HERVs, those that are actively transcribing, have been associated with various cancers. Suppression mechanisms that control HERV expression often fail or become more permissive in tissues where expression should be restricted. Previous studies have identified HERV expression in breast cancer tissues, whereas normal tissue HERV expression remained suppressed. In addition, studies of DNA hypermethylation have correlated with the ability to contribute to cancer development. Hypermethylation of several tumor suppressor genes occurs frequently in cancers and alterations in promoter regions could contribute to the development of …

Microbial Nad Metabolism: Lessons From Comparative Genomics, Francesca Gazzaniga, Rebecca Stebbins, Sheila Z. Chang, Mark A. Mcpeek, Charles Brenner

Dartmouth Scholarship

NAD is a coenzyme for redox reactions and a substrate of NAD-consuming enzymes, including ADP-ribose transferases, Sir2-related protein lysine deacetylases, and bacterial DNA ligases. Microorganisms that synthesize NAD from as few as one to as many as five of the six identified biosynthetic precursors have been identified. De novo NAD synthesis from aspartate or tryptophan is neither universal nor strictly aerobic. Salvage NAD synthesis from nicotinamide, nicotinic acid, nicotinamide riboside, and nicotinic acid riboside occurs via modules of different genes. Nicotinamide salvage genes nadV and pncA, found in distinct bacteria, appear to have spread throughout the tree of life …

Cloning And Expression Of A Putative Exported Protein Coding Gene Sas1089 From An Invasive Community Associated Staphylococcus Aureus Strain Mssa476, Nailah Alzaki

All-Inclusive List of Electronic Theses and Dissertations

Originally, methicillin resistant Staphylococcus aureus (MRSA) occurred primarily in the hospital setting and was designated hospital- associated MRSA (HA-MRSA). In recent years, isolates of Staphylococcus aureus from the community (CA-MRSA), found to be methicillin resistant, are not as resistant tooth~ antibiotics as HA-MRSA. However, community strains are noted for their invasiveness causing soft tissue infections with propensity for invasion to deeper sites.

Cd19 Signaling Is Impaired In Murine Peritoneal And Splenic B-1 B Lymphocytes, Trivikram Dasu, Vishal Sindhava, Stephen H. Clarke, Subbarao Bondada

Microbiology, Immunology, and Molecular Genetics Faculty Publications

B-1 cells reside predominantly within the coelomic cavities, tonsils, Peyer's patches, spleen (a minor fraction – ∼5%) and are absent in the lymph nodes. They are the primary sources of natural IgM in the body. B-1 cells express polyreactive B cell receptors (BCRs) that cross react with self-antigens and are thus implicated in auto-immune disorders. Previously, we reported that peritoneal B-1 cells are deficient in CD19-mediated intracellular signals leading to Ca²⁺ mobilization. Here, we find that splenic B-1 cells, like peritoneal B-1 cells, are defective in Ca²⁺ release upon B cell activation by co-cross-linking BCR and CD19. In …

Lipid Nanoparticles With Accessible Nickel As A Vaccine Delivery System For Single And Multiple His-Tagged Hiv Antigens, Weili Yan, Anekant Jain, Ronan O'Carra, Jerold Woodward, Wenxue Li, Guanhan Li, Avindra Nath, Russell J. Mumper

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Lipid-based nanoparticles (NPs) with a small amount of surface-chelated nickel (Ni-NPs) were developed to easily formulate the HIV his-tagged Tat protein, as well as to formulate and co-deliver two HIV antigens (his-p24 and his-Nef) on one particle. Female BALB/c mice were immunized by s.c. injection with his-Tat/Ni-NP formulation (1.5 μg Tat-his/mouse) and control formulations on day 0 and 14. The day 28 anti-Tat specific IgG titer with his-Tat/Ni-NP was significantly greater than that with Alum/his-Tat. Furthermore, splenocytes from his-Tat/Ni-NP immunized mice secreted significantly higher IFN-γ than those from mice immunized with Alum/his-Tat. Although Ni-NPs did not show better adjuvant activity …

Dna-Binding By Haemophilus Influenzae And Escherichia Coli Ybab, Members Of A Widely-Distributed Bacterial Protein Family, Anne E. Cooley, Sean P. Riley, Keith Kral, M. Clarke Miller, Edward Demoll, Michael G. Fried, Brian Stevenson

Microbiology, Immunology, and Molecular Genetics Faculty Publications

BACKGROUND: Genes orthologous to the ybaB loci of Escherichia coli and Haemophilus influenzae are widely distributed among eubacteria. Several years ago, the three-dimensional structures of the YbaB orthologs of both E. coli and H. influenzae were determined, revealing a novel "tweezer"-like structure. However, a function for YbaB had remained elusive, with an early study of the H. influenzae ortholog failing to detect DNA-binding activity. Our group recently determined that the Borrelia burgdorferi YbaB ortholog, EbfC, is a DNA-binding protein. To reconcile those results, we assessed the abilities of both the H. influenzae and E. coli YbaB proteins to bind DNA …

Localization And Expression Of The Aer Receptor In Escherichia Coli, Daniel Salcedo

Loma Linda University Electronic Theses, Dissertations & Projects

In Escherichia coli, chemotactic movement towards an energetically-favorable environment is mediated by five transmembrane chemoreceptors. These sensory proteins respond to numerous environmental signals, including amino acids, sugars, and pH. The aerotaxis receptor, Aer, is an intracellular sensor that responds to oxygen concentration and other parameters affecting cellular energy levels. Bacterial chemotaxis receptors form dimeric signaling units that organize into tetramers and hexamers and form large clusters at the cell poles. A cluster arrangement could increase receptor sensitivity by lateral communication between dimers, thus amplifying the signal from one dimer. We have shown that Aer forms dimers, trimer of dimers, …

Role Of The Genomics Revolution In Pharmaceutics, Daniel A. Brazeau, Gayle A. Brazeau

Pharmaceutical Sciences Faculty Publications

Highlights the examples of Thiopurine S-methyltransferase (TPMT) and Warfarin as a means of describing some of the problems that are common to many pharmacogenetic cases. The pharmacogenetic literature contains many examples of confusing, or even contradictory, studies that arise due to unknown environmental factors that result in poor outcomes; drugs whose metabolism/transport are affected by multiple genes in multiple pathways; and clinically important genes that have many rare allelic variants with similar phenotypes variation in the frequencies of allelic variants among ethnic groups that mask the role of any one variant. These issues are common to most gene/drug dynamics and …

The C. Elegans Snail Homolog Ces-1 Can Activate Gene Expression In Vivo And Share Targets With Bhlh Transcription Factors, John S. Reece-Hoyes, Bart Deplancke, M. Inmaculada Barrasa, Julia Hatzold, Ryan B. Smit, H Efsun Arda, Patricia A. Pope, Jeb Gaudet, Barbara Conradt, Albertga J.M. Walhout

Dartmouth Scholarship

Snail-type transcription factors (TFs) are found in numerous metazoan organisms and function in a plethora of cellular and developmental processes including mesoderm and neuronal development, apoptosis and cancer. So far, Snail-type TFs are exclusively known as transcriptional repressors. They repress gene expression by recruiting transcriptional co-repressors and/or by preventing DNA binding of activators from the basic helix-loop-helix (bHLH) family of TFs to CAGGTG E-box sequences. Here we report that the Caenorhabditis elegans Snail-type TF CES-1 can activate transcription in vivo. Moreover, we provide results that suggest that CES-1 can share its binding site with bHLH TFs, in different tissues, …

Characterization Of Conserved Properties Of Hemagglutinin Of H5n1 And Human Influenza Viruses: Possible Consequences For Therapy And Infection Control, Veljko Veljkovic, Nevena Veljkovic, Claude P. Muller, Sybille Müller, Sanja Glisic, Vladimir Perovic, Heinz Köhler

Microbiology, Immunology, and Molecular Genetics Faculty Publications

BACKGROUND: Epidemics caused by highly pathogenic avian influenza virus (HPAIV) are a continuing threat to human health and to the world's economy. The development of approaches, which help to understand the significance of structural changes resulting from the alarming mutational propensity for human-to-human transmission of HPAIV, is of particularly interest. Here we compare informational and structural properties of the hemagglutinin (HA) of H5N1 virus and human influenza virus subtypes, which are important for the receptor/virus interaction.

RESULTS: Presented results revealed that HA proteins encode highly conserved information that differ between influenza virus subtypes H5N1, H1N1, H3N2, H7N7 and defined an …

Borrelia Burgdorferi Ebfc Defines A Newly-Identified, Widespread Family Of Bacterial Dna-Binding Proteins, Sean P. Riley, Tomasz Bykowski, Anne E. Cooley, Logan H. Burns, Kelly Babb, Catherine A. Brissette, Amy Bowman, Matthew L. Rotondi, M. Clarke Miller, Edward Demoll, Kap Lim, Michael G. Fried, Brian Stevenson

Microbiology, Immunology, and Molecular Genetics Faculty Publications

The Lyme disease spirochete, Borrelia burgdorferi, encodes a novel type of DNA-binding protein named EbfC. Orthologs of EbfC are encoded by a wide range of bacterial species, so characterization of the borrelial protein has implications that span the eubacterial kingdom. The present work defines the DNA sequence required for high-affinity binding by EbfC to be the 4 bp broken palindrome GTnAC, where ‘n’ can be any nucleotide. Two high-affinity EbfC-binding sites are located immediately 5′ of B. burgdorferi erp transcriptional promoters, and binding of EbfC was found to alter the conformation of erp promoter DNA. Consensus EbfC-binding …

Velo-Cardio-Facial Syndrome, Doron Gothelf, Amos Frisch, Elena Michaelovsky, Abraham Weizman, Robert J. Shprintzen

Communication Disorders Faculty Publications

Velocardiofacial syndrome (VCFS), also known as DiGeorge, conotruncal anomaly face, and Cayler syndromes, is caused by a microdeletion in the long arm of Chromosome 22. We review the history of the syndrome from the first clinical reports almost half a century ago to the current intriguing molecular findings associating genes from the microdeletion region and the physical and neuropsychiatric phenotype of the syndrome. Velocardiofacial syndrome has a wide spectrum of more than 200 physical manifestations including palate and cardiac anomalies. Yet, the most challenging manifestations of VCFS are the learning disabilities and neuropsychiatric disorders. As VCFS is relatively common and …

Long-Term Survival After Multidisciplinary Management Of Resected Pancreatic Adenocarcinoma, Matthew H G Katz, Huamin Wang, Jason B Fleming, Charlotte C Sun, Rosa F Hwang, Robert A Wolff, Gauri Varadhachary, James L Abbruzzese, Christopher H Crane, Sunil Krishnan, Jean-Nicolas Vauthey, Eddie K Abdalla, Jeffrey E Lee, Peter W T Pisters, Douglas B Evans

Faculty, Staff and Student Publications

INTRODUCTION: Actual 5-year survival rates of 10-18% have been reported for patients with resected pancreatic adenocarcinoma (PC), but the use of multimodality therapy was uncommon in these series. We evaluated long-term survival and patterns of recurrence in patients treated for PC with contemporary staging and multimodality therapy.

METHODS: We analyzed 329 consecutive patients with PC evaluated between 1990 and 2002 who underwent resection. Each received a multidisciplinary evaluation and a standard operative approach. Pre- or postoperative chemotherapy and/or chemoradiation were routine. Surgical specimens of 5-year survivors were re-reviewed. A multivariate model of factors associated with long-term survival was constructed.

RESULTS: …

When Old-Order Amish Meet New Order Science: Genetic Maladies And The Amish Dilemma, Kelley Downey

Undergraduate Research Conference

The Old World Amish, an Anabaptist Christian domination in the United States and Canada are know for their plain dress, avoidance of modern technology, and separation from the mainstream society.

A traditional agricultural religious group, the Old World Amish maintains isolation from the rest of the community. Financially well-off, they are homogeneous on education, occupation by gender, age at marriage, religion/ethnicity, and health care.

Although the Amish strongly discourage marriage between close cousins, the Lancaster Amish genealogy is described as mutational - inbreeding from multiple, remote connections rather than close consanguinity (first-cousin marriages).

Amish settlements have been identified with certain …

Comparison Of Replication-Competent, First Generation, And Helper-Dependent Adenoviral Vaccines, Eric A. Weaver, Pramod N. Nehete, Stephanie S. Buchl, Julien S. Senac, Donna Palmer, Philip Ng, K. Jagannadha Sastry, Michael A. Barry

Nebraska Center for Virology: Faculty Publications

All studies using human serotype 5 Adenovirus (Ad) vectors must address two major obstacles: safety and the presence of pre-existing neutralizing antibodies. Helper-Dependent (HD) Ads have been proposed as alternative vectors for gene therapy and vaccine development because they have an improved safety profile. To evaluate the potential of HD-Ad vaccines, we compared replication-competent (RC), first-generation (FG) and HD vectors for their ability to induce immune responses in mice. We show that RC-Ad5 and HD-Ad5 vectors generate stronger immune responses than FG-Ad5 vectors. HD-Ad5 vectors gave lower side effects than RC or FG-Ad, producing lower levels of tissue damage and …

Detection Of Cwd Prions In Urine And Saliva Of Deer By Transgenic Mouse Bioassay, Nicholas J. Haley, Davis M. Seelig, Mark D. Zabel, Glenn C. Telling, Edward A. Hoover

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Chronic wasting disease (CWD) is a prion disease affecting captive and free-ranging cervids (e.g. deer, elk, and moose). The mechanisms of CWD transmission are poorly understood, though bodily fluids are thought to play an important role. Here we report the presence of infectious prions in the urine and saliva of deer with chronic wasting disease (CWD). Prion infectivity was detected by bioassay of concentrated, dialyzed urine and saliva in transgenic mice expressing the cervid PrP gene (Tg[CerPrP] mice). In addition, PrP(CWD) was detected in pooled and concentrated urine by protein misfolding cyclic amplification (PMCA). The concentration of abnormal prion protein …

Integral And Peripheral Association Of Proteins And Protein Complexes With Yersinia Pestis Inner And Outer Membranes, Rembert Pieper, Shih-Ting Huang, David J. Clark, Jeffrey M. Robinson, Hamid Alami, Prashanth P. Parmar, Moo-Jin Suh, Srilatha Kuntumalla, Christine L. Bunai, Robert D. Perry, Robert D. Fleischmann, Scott N. Peterson

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Yersinia pestis proteins were sequentially extracted from crude membranes with a high salt buffer (2.5 M NaBr), an alkaline solution (180 mM Na2CO3, pH 11.3) and membrane denaturants (8 M urea, 2 M thiourea and 1% amidosulfobetaine-14). Separation of proteins by 2D gel electrophoresis was followed by identification of more than 600 gene products by MS. Data from differential 2D gel display experiments, comparing protein abundances in cytoplasmic, periplasmic and all three membrane fractions, were used to assign proteins found in the membrane fractions to three protein categories: (i) integral membrane proteins and peripheral membrane proteins with low solubility in …

Accumulation Of Rhodopsin In Late Endosomes Triggers Photoreceptor Cell Degeneration, Yashodhan Chinchore, Amitavo Mitra, Patrick J. Dolph, Norbert Perrimon

Dartmouth Scholarship

Progressive retinal degeneration is the underlying feature of many human retinal dystrophies. Previous work using Drosophila as a model system and analysis of specific mutations in human rhodopsin have uncovered a connection between rhodopsin endocytosis and retinal degeneration. In these mutants, rhodopsin and its regulatory protein arrestin form stable complexes, and endocytosis of these complexes causes photoreceptor cell death. In this study we show that the internalized rhodopsin is not degraded in the lysosome but instead accumulates in the late endosomes. Using mutants that are defective in late endosome to lysosome trafficking, we were able to show that rhodopsin accumulates …

Mutual Information For Testing Gene-Environment Interaction, Xuesen Wu, Li Jiin, Momiao Xiong

Faculty, Staff and Student Publications

Despite current enthusiasm for investigation of gene-gene interactions and gene-environment interactions, the essential issue of how to define and detect gene-environment interactions remains unresolved. In this report, we define gene-environment interactions as a stochastic dependence in the context of the effects of the genetic and environmental risk factors on the cause of phenotypic variation among individuals. We use mutual information that is widely used in communication and complex system analysis to measure gene-environment interactions. We investigate how gene-environment interactions generate the large difference in the information measure of gene-environment interactions between the general population and a diseased population, which motives …

A Role For The Igh Intronic Enhancer E Mu In Enforcing Allelic Exclusion, Fubin Li, Laurel A. Eckhardt

Publications and Research

The intronic enhancer (E mu) of the immunoglobulin heavy chain (IgH) locus is critical for V region gene assembly. To determine E mu's subsequent functions, we created an Igh allele with assembled V(H) gene but with E mu removed. In mice homozygous for this E mu-deficient allele, B cell development was normal and indistinguishable from that of mice with the same V(H) knockin and E mu intact. In mice heterozygous for the E mu-deficient allele, however, allelic exclusion was severely compromised. Surprisingly, this was not a result of reduced suppression of V-DJ assembly on the second allele. Rather, the striking …

Understanding The Physical Properties That Control Protein Crystallization By Analysis Of Largescale Experimental Data, W. Nicholson Price Ii, Yang Chen, Samuel K. Handelman, Helen Neely, Philip Manor, Richard Karlin, Rajesh Nair, Jinfeng Liu, Michael Baran, John Everett, Saichiu N. Tong, Farhad Forouhar, Swarup S. Swaminathan, Thomas Acton, Rong Xiao, Joseph R. Luft, Angela Lauricella, George T. Detitta, Burkhard Rost, Gaetano T. Montelione, John T. Hunt

Law Faculty Scholarship

Crystallization is the most serious bottleneck in high-throughput protein-structure determination by diffraction methods. We have used data mining of the large-scale experimental results of the Northeast Structural Genomics Consortium and experimental folding studies to characterize the biophysical properties that control protein crystallization. This analysis leads to the conclusion that crystallization propensity depends primarily on the prevalence of well-ordered surface epitopes capable of mediating interprotein interactions and is not strongly influenced by overall thermodynamic stability. We identify specific sequence features that correlate with crystallization propensity and that can be used to estimate the crystallization probability of a given construct. Analyses of …

X4 Human Immunodeficiency Virus Type 1 Gp120 Down-Modulates Expression And Immunogenicity Of Codelivered Antigens, Avi-Hai Hovav, Michael Santosuosso, Maytal Bivas-Benita, Andre Plair, Alex Cheng, Mazal Elnekave, Elda Righi, Tao Chen, Satoshi Kashiwagi, Michael W. Panas, Shi-Hua Xiang, Karina Furmanov, Norman L. Letvin, Mark C. Poznansky

Nebraska Center for Virology: Faculty Publications

In order to increase the immune breadth of human immunodeficiency virus (HIV) vaccines, strategies such

as immunization with several HIV antigens or centralized immunogens have been examined. HIV-1 gp120

protein is a major immunogen of HIV and has been routinely considered for inclusion in both present and

future AIDS vaccines. However, recent studies proposed that gp120 interferes with the generation of immune

response to codelivered antigens. Here, we investigate whether coimmunization with plasmid-encoded gp120

alters the immune response to other coadministered plasmid encoded antigens such as luciferase or ovalbumin

in a mouse model. We found that the presence of gp120 …

Identification And Characterization Of A New Kaposi’S Sarcoma-Associated Herpesvirus Replication And Transcription Activator (Rta)- Responsive Element Involved In Rta-Mediated Transactivation, Hui-Ju Wen, Veenu Minhas, Charles Wood

Nebraska Center for Virology: Faculty Publications

Kaposi’s sarcoma-associated herpesvirus (KSHV) replication and transcription activator (RTA) is well established as a key transcriptional activator that regulates the KSHV life cycle from latency to lytic replication. It is expressed immediately after infection and activates a number of viral genes leading to virus replication. The RTA-responsive element (RRE) in the RTA target gene promoters is critical for RTA to mediate this transactivation. A number of non-conserved RREs have been identified in various RTA-responsive promoters, and AT-rich sequences have been proposed to serve as RTA targets, but no consensus RRE sequence has been identified so far. Two nonconserved RREs (RRE1 …

Use Of Average Mutual Information For Studying Changes In Hiv Populations, Khalid Sayood, Federico Hoffman, Charles Wood

Nebraska Center for Virology: Faculty Publications

Average mutual information (AMI) has been used in a number of applications in bioinformatics. In this paper we present its use to study genetic changes in populations; in particular populations of HIV viruses. Disease progression of HIV-1 infection in infants can be rapid resulting in death within the the first year, or slow, allowing the infant to survive beyond the first year. We study the development of rapid and slow progressing HIV population using AMI charts based on average mutual information among amino acids in the env gene from a population of 1142 clones derived from seven infants with slow …

Comparison Of Replication-Competent, First Generation, And Helper-Dependent Adenoviral Vaccines, Eric A. Weaver, Pramod N. Nehete, Stephanie S. Buchl, Julien S. Senac, Donna Palmer, Philip Ng, K. Jagannadha Sastry, Michael A. Barry

Nebraska Center for Virology: Faculty Publications

All studies using human serotype 5 Adenovirus (Ad) vectors must address two major obstacles: safety and the presence of pre-existing neutralizing antibodies. Helper-Dependent (HD) Ads have been proposed as alternative vectors for gene therapy and vaccine development because they have an improved safety profile. To evaluate the potential of HD-Ad vaccines, we compared replication-competent (RC), first-generation (FG) and HD vectors for their ability to induce immune responses in mice. We show that RC-Ad5 and HD-Ad5 vectors generate stronger immune responses than FG-Ad5 vectors. HD-Ad5 vectors gave lower side effects than RC or FG-Ad, producing lower levels of tissue damage and …

Primate Phylogenomics: Developing Numerous Nuclear Non-Coding, Non-Repetitive Markers For Ecological And Phylogenetic Applications And Analysis Of Evolutionary Rate Variation, Zuogang Peng, Navin Elango, Derek E. Wildman, Soojin V. Yi

Wayne State University Associated BioMed Central Scholarship

Abstract

Background

Genetic analyses are often limited by the availability of appropriate molecular markers. Markers from neutrally evolving genomic regions may be particularly useful for inferring evolutionary histories because they escape the constraints of natural selection. For the majority of taxa however, obtaining such markers is challenging. Advances in genomics have the potential to alleviate the shortage of neutral markers. Here we present a method to develop numerous markers from putatively neutral regions of primate genomes.

Results

We began with the available whole genome sequences of human, chimpanzee and macaque. Using computational methods, we identified a total of 280 potential …

The Association Of Human Leukocyte Antigen(Hla) Alleles And Type 2 Diabetes Mellitus (T2dm) Among Mexican Americans (Ma), Kantibhai Motiram Patel

Open Access Theses & Dissertations

The epidemic of type 2 diabetes mellitus (T2DM) is ranked as a major public health priority across the United States and especially in the El Paso, Texas region. The risk for the development of T2DM is greater in minority groups, particularly among Mexican Americans (MA) who comprise approximately 78% of El Paso's population. The growing incidence of T2DM in this group is typically attributed to increase in weight (obesity). The incidence of diabetes may also be influenced by genetic factors that are unique to this group. Several earlier studies have identified genetic markers for type 1 diabetes mellitus (T1DM). These …

A Discourse On The Public Nature Of Research In Contemporary Life Science: A Law-Policy Proposal To Promote The Public Nature Of Science In An Era Of Academia-Industry Integration, Michael J. Malinowski

Journal Articles

This article addresses the impact of integration of academia, industry, and government on the public nature of research. The article concludes that, while the integration has benefited science immensely, regulatory measures should be taken to restore the public nature of research in an age of integration.

Human Ubc9 Contributes To Production Of Fully Infectious Human Immunodeficiency Virus Type 1 Virions, Tareq Jaber, Christopher R. Bohl, Gentry L. Lewis, Charles Wood, John T. West Jr., Robert A. Weldon Jr.

Nebraska Center for Virology: Faculty Publications

Ubc9 was identified as a cellular protein that interacts with the Gag protein of Mason-Pfizer monkey virus. We show here that Ubc9 also interacts with the human immunodeficiency virus type 1 (HIV-1) Gag protein and that their interaction is important for virus replication. Gag was found to colocalize with Ubc9 predominantly at perinuclear puncta. While cells in which Ubc9 expression was suppressed with RNA interference produced normal numbers of virions, these particles were 8- to 10-fold less infectious than those produced in the presence of Ubc9. The nature of this defect was assayed for dependence on Ubc9 during viral assembly, …