Christina King Smith, Ph.D. Associate Professor of Biology

Dr Christina King Smith
Professor
Department Advisor and Coordinator
Department of Biology
Office - Rm 222 Science Center
Research Lab - Rm 216 Science Center
Phone:   610-660-1118
E-mail: csmith@sju.edu

Education:

    - B.S. (1982) in Biology, Bucknell University, Lewisburg, PA
    - M.S.(1985) in Marine Studies, University of Delaware
    - Ph.D. (1992) in Biological Sciences, University of Maryland.

Professional Experience:

    - Post-Doctoral Fellow (1992 - 1995), Department of Molecular and Cell Biology, University of California at Berkley.
    - Assistant (1996 - 2002) and Associate (2002 - present) Professor, Assistant Chair and Advising Coordinator (2005 - present), Department of Biology, Saint Joseph's University, Philadelphia, PA.

Courses Taught:

Research interests:  the cytoskeleton and cell motility, especially actin dependent organelle transport and actin/myosin dynamics in lamellipodia

Research in my laboratory is directed in two major areas:  1) understanding mechanisms of actin- dependent organelle motility, and 2) investigating the role of myosin 1 isoforms in lamellipodial dynamics.  For organelle motility studies, we use retinal pigment epithelial (RPE) cells from fish.  These cells are found at the back of vertebrate eyes, and contain numerous pigment granules (melanosomes) that undergo mass migrations in reponse to light.  RPE cells can be isolated from eyes of sunfish, dissociated, and cultured as single cells.  Melanosome movement can be stimulated in vitro.  Both aggregation and dispersion of melanosomes in the long apical projections of isolated cells requires an intact actin cytoskeleton.  Questions we are addressing include:

    • what are the roles of myosin motors in organelle motility?
    • studies thus far have been conducted with RPE cells from sunfish, (Lepomis spp.).  Can we isolate and culture RPE cells from zebrafish, to allow the use of zebrafish mutants in RPE motility studies?
    • do actin dynamics, including actin retrograde flow, play a role in motility?
    • melanosome aggregation is stimulated by underivatized cAMP.  Cyclic AMP presumably stimulates phosphorylation by protein kinaseA.  What are the targets of PKA?

 

            The second area of interest represents a new direction of research in my laboratory: to understand the role of myosin 1 isoforms in lamellipodial dynamics.  Working with collaborators, questions we are investigating are centered on understanding the distribution and role of myosin 1 isoforms in lamellipodia of B16F1 mouse melanoma cells. 

 

Selected publications: (*indicates undergraduate students; **indicates masters students)

  • Barsoum, I.B**. and C. King-Smith.  2007.  Myosin II and rho kinase are required for melanosome aggregation in fish retinal pigment epithelial (RPE) cells. Cell Motility  and the Cytoskeleton 64:868-879.
  • McNeil, E.L*, D. Tacelosky*, P. Basciano*, B. Biallas**, R. Williams*, P. Damiani*, S. Deacon*, C. Fox*, B. Stewart*, N. Petruzzi*, C. Osborn*, K. Klinger*, J.R. Sellers, and C. King-Smith.  2004.  Actin-dependent motility of melanosomes from fish retinal pigment epithelial (RPE) cells investigated using in vitro motility assays.  Cell Motility and the Cytoskeleton  58:71-82.
  • Basciano, P.A.* and C. King-Smith.  2002.  Actin-dependent, retrograde motility of surface-attached beads and aggregating pigment granules in dissociated teleost retinal pigment epithelial cells.  Pigment Cell Research 15:162-173.
  • King-Smith, C., P. Basciano*, N. Pham*.  2001.  Effect of the actin stabilizing drug, jasplakinolide, on pigment granule motility in the retinal pigment epithelium (RPE) of green sunfish, Lepomis cyanellus.  Pigment  Cell Research 14:14-22.
  • King-Smith, C., P. Paz**, C. W. Lee*, W. Lam*, and B. Burnside.  1997.  Bi-directional pigment granule migration in isolated retinal pigment epithelial (RPE) cells requires actin but not microtubules.  Cell Motility and the Cytoskeleton 38:229-249.
  • King-Smith, C. and T. W. Cronin.  1996.  Pigment granule migration in crustacean photoreceptors requires calcium.  Visual Neuroscience 13:43-49.
  • King-Smith, C., D. Garcia**, P. Chen*, H. Rey**, and B. Burnside.  1996.  Calcium-independent regulation of pigment granule aggregation and dispersion in teleost retinal pigment epithelial cells.  Journal of Cell Science 109:33-43.
  • King-Smith, C., L. Bost-Usinger and B. Burnside.  1995.  Expression of kinesin heavy chain isoforms in retinal pigment epithelial cells of teleosts.  Cell Motility and the Cytoskeleton 31:66-81.

Recent Abstracts

  • Gannon, P* and C. King-Smith.  2006.  Concanavalin A inhibits melanosome aggregation in isolated retinal pigment epithelial cells.  Molecular Biology of the Cell 17 (Suppl) L59 (Tuesday).  (Late Abstracts, The American Society for Cell Biology 46th Annual Meeting)
  • Vagnozzi, R* and C. King-Smith.  2006.  Actin filament polarity in retinal pigment epithelial cells of green sunfish, Lepomis cyanellus.  Molecular Biology of the Cell 17 (Suppl) 1653 (CD-ROM)
  • Fox, C.D.*, P. Damiani*, R.V. Williams*, B.M. Biallas*, D. M. Tacelosky*, and C. King-Smith.  2003.  Melanosome motility and identification of the small GTPase, rab27a, in retinal pigment epithelial (RPE) cells of sunfish (Lepomis spp.) and zebrafish (Danio rerio).  Molecular Biology of the Cell  14 (Suppl) 332a-333a.
  • Barsoum, I.B.* and C. King-Smith.  2003.  Blebbistatin, a myosin II inhibitor, blocks melanosome aggregation but not dispersion in fish retinal pigment epithelial (RPE) cells.  Molecular Biology of the Cell 14 (Suppl) 332a.
  • Fox, C.* Damiani, P.*, Williams, R.* and  King-Smith, C..  2003.  Using SDS-PAGE and immunoblotting to test cross-reactivity of proteins important in pigment granule transport in retinal pigment epithelial cells of fish.  Proceedings of the National Conference on Undergraduate Research, Salt Lake City, Utah.
  • Tacelosky, D.* and King-Smith, C.  2003. Observing Actin-dependent Motility of Melanosomes Isolated From Retinal Pigment Epithelial Cells of Green Sunfish, Lepomis Cyanellus, in a Sliding Filament Assay. Proceedings of the National Conference on Undergraduate Research, Salt Lake City, Utah.
  • King-Smith, C.  2002.  Using the Personal Response System (PRS) for Learning and Assessment in Undergraduate Cell Biology and Genetics Courses.  Molecular Biology of the Cell 13 (Suppl) 414a-415a.
  • McElwee, K*. and C. King-Smith.  2001.  Affects of micromanipulation and microsurgery on pigment granule movement within projections of isolated retinal pigment epithelial cells.  Molecular Biology of the Cell 12 (Suppl):  165a-166a.
  • McNeil, E.L.*, Klinger, C.A. *, Stewart, B.L*., Sellers, J.R., and C. King-Smith.  2001.  Pigment granules from fish retinal pigment epithelial (RPE) cells undergo plus-end directed motility in assays using the Characean alga, Nitella axillaris.  Molecular Biology of the Cell 12 (Suppl): 165a.
  • Stidham, R.S*., Campbell, A., and C. King-Smith.  2001.  Developing techniques for expression of green fluorescent protein in retinal pigment epithelial cells of Lepomis cyanellus".  In .  Proceedings of the National Conference on Undergraduate Research
  • McNeil, E*., Basciano, P*., Sellers, J.R. and C. King-Smith.  2000.  Isolated pigment granules from teleost retinal pigment epithelial cells move along actin cables of the alga, Nitella axillaris.  Molecular Biology of the Cell 11 (Suppl):355a.

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