[Kenneth Belanger]Kenneth Belanger (Associate Professor)

Department of Biology, Colgate University

Phone: (315) 228-7347 Fax: (315) 228-7997

E-Mail: KBelanger@mail.colgate.edu

Research Interests: Understanding how the intracellular movement of macromolecules influences cell structure and function. Specifically, how nuclear protein import is regulated and how vesicle mediated secretion contributes to asymmetric cell growth during development.  [Details]

Teaching Interests: Developmental biology, cellular biology, molecular biology, genetics [Details]

Student Research   Publications  Grants  

Colgate Teaching & Research Directory  

Kenneth Belanger

Research Interests:

Research in my lab is focused on understanding how molecules are targeted to particular locations inside cells.  Most activities taking place inside cells are carried out by proteins, which are large molecules synthesized in the cytoplasm of eukaryotic cells.  Most of these proteins perform their functions at specific sites within the cell, such as within a specific organelle or on a particular cellular membrane.  In order for a protein to function at a particular location, it must be targeted to that location by a network of interacting molecules within the cell.  Our research addresses how this “network” of targeting molecules functions. Specifically, we are interested in how large molecules, such as proteins and RNAs, are transported between the cytoplasm and nucleus of eukaryotic cells.

Gaining an understanding of the mechanism of nuclear transport is fundamental to our comprehension of important cellular events, including regulation of gene expression, response of cells to their environment, and even infection of cells by certain types of viruses, including HIV.  In eukaryotic cells, proteins and RNAs must constantly be transported across the nuclear envelope separating the nucleus from the cytoplasm. The RNA molecules transcribed from genes in the nucleus must be exported to the cytoplasm before they can be translated into the proteins that carry out most cell functions. Specific proteins, synthesized in the cytoplasm, must be imported into the nucleus to carry out such functions as DNA replication, RNA transcription and processing, ribosome assembly, and regulation of nuclear structure (View a video).  These RNAs and proteins cross the nuclear envelope through a large, multi-protein channel termed the nuclear pore complex (NPC) [See figure -Schematic diagram of nuclear pore complex structure. From M. Rout and J Aitchison. (2001) J. Biol. Chem., Vol. 276 (20): 16593-16596. (Full text article at http://www.jbc.org/cgi/content/full/276/20/16593)].  #

 

My lab is focused on understanding how the proteins comprising the NPC interact with each other and with soluble “nuclear transport factors” to mediate translocation of proteins and RNA into and out of the nucleus.

The primary method we have used to examine what factors are involved in nuclear transport is to perform genetic screens to identify mutations that affect nuclear transport in the yeast Saccharomyces cerevisiae. By identifying the genes that are mutated in yeast nuclear transport mutants, we can then begin to understand the function performed by the proteins encoded by these genes.  Importantly, nuclear transport occurs by the same mechanism in yeast as it does in other eukaryotic cells, so identifying these transport proteins and their functions in yeast tells us much about how nuclear transport occurs in our own cells. 

Genes that we have identified in our genetic screens encode both NPC proteins and soluble proteins involved in nuclear transport. Students in the lab are continuing to work with these mutants in three different types of projects, each of which uses a different technique to ask how a particular protein might function in nuclear transport.  These projects include:

1. Examination of intracellular protein localization by fluorescence light microscopy.

Defects in nuclear transport can be detected by observing altered localization of proteins that normally travel between the nucleus and cytoplasm. We can observe the intracellular localization of a particular protein by expressing it as a fusion with “green fluorescent protein” (GFP) and then observing the location of the glowing GFP in the cell.  We are currently looking at changes in localization of specific proteins in cells that are normal versus cells that contain mutations in specific nuclear pore complex proteins.

2. Molecular cloning of genes encoding proteins involved in nuclear transport. We have yet to identify many of the genes we have altered in our nuclear transport mutants. Students are currently using “libraries” of yeast genomic DNA to isolate these altered genes and begin the process of characterizing the function of the proteins they encode.

[ Map of a small region of yeast chromosome X showing NUP82/NLE4 and surrounding genes.  NUP82 encodes a nuclear pore complex protein which is important for efficient nuclear transport. (Chromosome map generated by the Saccharomyces Genome Database: http://yeastgenome.org )  ]

3. Examining physical interactions between nuclear transport proteins using biochemistry.

If two proteins are involved in a cellular activity, they will often physically interact or “bind” to each other to carry out that activity. We are testing for interactions between specific nuclear pore complex proteins and soluble transport factors in order to determine if such interactions are important for the translocation of molecules across the NPC. We not only are utilizing these biochemical assays in our research lab, but also have incorporated an experiment examining interactions between nuclear transport factors into our Biology 212 (Molecules, Cells, and Genes) teaching laboratory (see “Teaching Interests” below).

In my research laboratory (like all labs at Colgate) the original, publishable research we perform is carried out by undergraduate students only. This means that students obtain hands-on experience in the lab, working closely with their research advisor to design and implement a research project in which they are intellectually invested and which utilizes laboratory skills they are interested in developing. 

Teaching Interests:

My teaching activities integrate my interest in the molecular events that take place inside cells with the resulting cellular activities that regulate the functions and the organization of individual cells, tissues, organs, and organisms.

Molecules, Cells, and Genes (Biol 212) is required of all Biology, Environmental Biology, and Molecular Biology concentrators and provides an in-depth introduction to eukaryotic cell function at the biochemical, macromolecular, and cellular levels. In lecture and lab, students are introduced to and asked to explore such topics as bioenergetics, enzyme kinetics, genes and regulation of gene expression, the cell cycle and the cytoskeleton, intracellular signaling and transport, and organelle structure and function. This class requires students to integrate their understanding of these seemingly diverse topics in order to explore basic cell function and to understand how different cells carry out different activities.

In Developmental Biology (Biol 324) we examine how changes in gene expression and cell-cell interactions influence both the function and the fate of cells in a developing embryo. The progression from single-celled zygote to multicellular organism containing millions of cells requires intricately coordinated molecular events. These events lead to the differentiation of specific cell types that are organized in a specified pattern and carry out specialized activities. Students in Developmental Biology examine such model developmental systems as sea urchins, fruit flies, amphibians, plants, and chicken embryos as they utilize a variety of molecular, microscopic, and microsurgical techniques to examine events occurring during early embryonic development.

I also participate in the first-year seminar (FSEM) program, teaching a CORE-Scientific Perspectives course entitled Cells and Human Development, and I offer a research tutorial (Intracellular Transport: Biol 483) in which upper-level students undertake semester-long research projects in my research lab.

All of these courses, from the first-year seminar to the research tutorial, emphasize student comprehension of the process by which scientific information is obtained. This means that we spend considerable time discussing not only what we understand about specific aspects of biology, but also how scientists investigate the functioning of molecules, cells, and organisms. All courses require reading of the primary scientific literature, design and/or execution of an original research experiment, and reporting on the results of the experiment in either the format of a primary journal article or as an oral report.  It is my goal to have students leave these courses not just having learned some new ideas about a particular area of biology, but also having taken a significant step toward “thinking like a biologist” and asking new questions about the field they have just spent a semester examining.

Student Research:

More than 25 students have performed research in my lab in the last three years, with many of those students earning departmental Honors or High Honors awards. Research students from my lab have gone on to graduate school at such institutions as Duke University, University of Pennsylvania, Cornell, Mayo Graduate School, Dartmouth, and Brandeis. Research students have also gained acceptance to medical schools including Johns Hopkins, Washington University, University of Michigan, University of Rochester, Temple, SUNY Upstate, and others.  Additional students have become employed upon graduation, with some at academic institutions (Harvard, UCLA, USC, Cornell, Roswell Cancer Institute, University of Chicago) and others in private industry (Pasteur-Aventis Pharmaceuticals).

 

Student Research Presentations:

Perazone T* (2004) Factors affecting the nuclear localization of Nma111-NLS. National Conference on Undergraduate Research. Indianapolis, IN.

MacDonald K* (2004) Ecm39 and its role in the transport of substances through the nuclear pore. National Conference on Undergraduate Research. Indianapolis, IN.

Belanger KD, Simmons LA*, Lichten LB*, Roth JK*, VanderPloeg KA*. (2003) Msn5/Kap142-mediated nuclear import utilizes a subset of nucleoporins distinct from the Nups required for Msn5-mediated export. American Society for Cell Biology Annual Meeting, San Francisco, CA.

Belanger KD, Simmons LA*, VanderPloeg KA*, Roth JK*, Lichten LB* (2003) Distinct sets of nucleoporins mediate Msn5-mediated import and export through the nuclear pore complex. Yeast Cell Biology, Cold Spring Harbor, NY.

Al-Greene N* (2003) The Spindle Pole Body Component NUD1 May Show A Functional Interaction With The Nuclear Transport Factor NUP1. National Conference on Undergraduate Research. Salt Lake City, UT.

VanderPloeg K* (2003) Elucidating the mechanism of nucleocytoplasmic transport: Subcellular localization of Msn5, Kap104, and Crm1 in S. cerevisiae mutants. National Conference on Undergraduate Research. Salt Lake City, UT.

Belanger KD, Davis LI, Simmons LA* (2002) “Identification of a functional and physical interaction between the nucleoporin Nup1 and the Mex67/Mtr2 export pathway.” Dynamic Organization of the Nucleus, Cold Spring Harbor, NY.

Roth, J.K.*, Lichten, L.B.*, and Belanger, K.D. (2002) “The karyopherin Msn5 is mislocalized in a mutant of the nucleoporin Nup82.” Dynamic Organization of the Nucleus, Cold Spring Harbor, NY.

Belanger, K.D., Cenera, C.M.*, Kenehan, S.*, and Davis, L.I. (2001) “Identification of NUP1 suppressor mutants in Saccharomyces cerevisiae.” American Society for Cell Biology Annual Meeting, Washington, DC.

Belanger, K., Verdetti, F.*, Dul, B.*, Farruggia, K.*, Kenna, M.A., and Davis, L.I. (1999) “Genetic analysis of nucleocytoplasmic transport in S. cerevisiae.” ASCB Annual Meeting, Washington, DC.

Recent Publications:

(* = undergraduate author)

Belanger KD, Simmons LA*, Roth JK*, VanderPloeg KA*, Lichten LB*, Fahrenkrog B. (Submitted) The karyopherin Msn5/Kap142 requires Nup82 for nuclear export and performs a function distinct from translocation in RPA protein import. Submitted to Molecular and Cellular Biology, June 2004.

Bembenek J, Li B, Kurischko C, Kang J, Raab JR*, Belanger KD, Luca FC, Yu H. (Submitted) Crm1-dependent nuclear export of Cdc14 is required for cytokinesis in budding yeast. Submitted to Cell, June 2004.

Belanger, K.D., Wyman, A., Sudol, M.*, Singla, S., and Quatrano, R. (2003) A signal peptide screen in Fucus distichus embryos reveals expression of glucanase, EGF domain-containing, and LRR receptor kinase-like polypeptides during asymmetric cell growth. Planta 217: 931 - 950.

Belanger, K.D. (2004) Model Organisms. Encyclopedia of Genetics. Ed. B.D. Ness. Salem Press, Pasadena, CA.

Belanger, K.D. and Quatrano, R.S. (2000) Membrane recycling occurs during asymmetric tip growth and cell plate formation in Fucus zygotes. Protoplasma: 212: 24-37.

Belanger, K.D. and Quatrano, R.S. (2000) Polarity: The role of localized secretion. Current Opinion in Plant Biology 3: 67-72.

Booth, J.W., Belanger, K.D., Sannella, M.I., and Davis, L.I. (1999) The yeast nucleoporin Nup2p is a docking site for nuclear export of importin-/Srp1p. Journal of Biological Chemistry 274(45): 32360-32367.

Belanger, K.D., Kenna, M.A., Wei, S., and Davis, L.I. (1994) Genetic and physical interactions between Srp1p and nuclear pore complex proteins Nup1p and Nup2p. Journal of Cell Biology 126: 619-630.

Grants Awarded:

National Science Foundation – Major Research Instrumentation Award: (July 2002 – June 2005). “Acquisition of fluorescence microscopy instrumentation for research and education in biology, geology, and neuroscience.”

National Institutes of Health -Academic Research Enhancement Award: (July 2001 – June 2005). “Examination of Nup1-mediated nucleocytoplasmic transport.”

Pennsylvania Academy of Sciences Undergraduate Research Award (Jan. 2000 – Jan 2001): “Examination of sperm-egg interactions in lower plants using antibodies recognizing cell surface antigens in brown algae.” Co-author with undergraduate student Melissa Lasota. Named 2000-2001 Outstanding Research Proposal by PAS.

NIH Postdoctoral Research Fellowship (November 1996 – August 1998): “Components required for asymmetric cell growth in Fucus.”