Return to: College of Biological Sciences: Medical School: U of M Home
Gold University of Minnesota M. Skip to main content.University of Minnesota. Home page.
One Stop | Directories | Search U of M 
 
GCD Home: DBC Home: Beckman Center Home: MCDBG Home: MCB Home
Ross Johnson, Ph.D.

Professor

Mailing Address:
University of Minnesota
Department of Genetics, Cell Biology, and Development
6-160 Jackson
321 Church St. SE
Minneapolis, MN 55455
USA
Education:
Ph.D., Iowa State University, 1968

Honors:
Office:
6-144 MCB
P: 612-624-1741
F: 612-625-5754

Email:
gaplab@tc.umn.edu

 Lab:
6-152 MCB
P: 612-624-9726

Areas of Research Strength:

Membranes, Receptors, and Membrane Transport
Cell Interactions
Developmental Mechanisms

back to top

Research Interests:

Johnson's Lab interests focus on the role of gap junctions in intercellular
communication. Within these junctions, membrane channels at the surface
of one cell are linked to similar channels in the membranes of opposed cells,
providing a pathway for the exchange of small molecules between cells. These
interactions are thought to be critical for the control of cell growth, for normal
embryonic development and for a variety of other processes. The biomedical
importance of gap junctions is underscored by recent work on gene "knock-outs"
in mice and on human mutations involving gap junction proteins. These mutations
are responsible for a number of genetic diseases.

Studies in the laboratory address the regulation of junctional communication,
both via mechanisms related to the assembly of gap junctions and to the "gating"
of junctional channels in mature junctions. Questions relate to the molecular
components of the developing junctions (e.g., members of the connexin gene family),
the requirements of assembly and the various controls over the process, including
membrane trafficking, connexin phosphorylation and signaling at the cell surface.
To illustrate, agents which stimulate connexin phosphorylation, e.g., tumor promoters,
dramatically modify both the assembly of junctions and the open state of junctional
channels. In addition, agents which elevate cAMP in cells are able to enhance gap
junction assembly, apparently through an effect on the trafficking of gap junction
precursors from inside to the plasma membrane (along microtubules). The
experimental work on this project is carried out using cultured cells.

Two other projects involve work of a developmental nature. The first addresses
the role of gap junction communication in the zebrafish embryo, specifically
in the notochord, which is a source of important signals in the early embryo.
The notochord influences the development of the neural tube and somites,
along with other cells. The second developmental project examines the role
of gap junctions in synchronizing the beating of neighboring heart cells,
as in adult heart.

back to top

Selected Publications:

Chatterjee, Valdimarsson, Finis, Krufka, Kozlowski, Johnson, and Lo. (2005). Structure, function and expression fo the zebrafish connexin43 gene. Devel. Dynamics. In press

Hur, KC, J. Shim and RG Johnson (2003). A potential roll for Cx43-hemichannels in staurosporin-induced apoptosis. Cell Communications and Adhesion 10:271-277.

Johnson, R.G., H.Y. Li, T. Myslajek, T.F. Liu, C. Elfgang, K. Willecke, M. Atkinson, D. Laird, and J.D. Sheridan, (2003) Gap junction hemichannels: Dye uptake is inhibited by connexin antibodies, stimulated mechanically and detected with nine different connexins. Submitted.

Johnson, R.G., R.A. Meyer, X.-R. Li, D. Preus, L. Tan, H.Y. Li, A.F. Paulson, D.W. Laird and J. Sheridan (2002) Gap junctions assemble in the presence of cytoskeletal inhibitors, but enhanced assembly requires microtubules. Exper. Cell Res. 275:67-80.

Lampe, P.D., Q. Qui, R.A. Meyer, E.M. TenBroek, T.F. Walseth, T.A. Starich, H.Y. Li, and R.G. Johnson (2001) Gap junction assembly: Pertussis toxin-sensitive G proteins regulate the distribution of connexin43 within cells. Amer. J. of Physiol. 281:C1211-22.

TenBroek, E., P.D. Lampe, Reynhout, J., T. Christen and R.G. Johnson. (2001) The C-terminus of connexin43 is required for the up-regulation of gap junction assembly by cAMP. J. of Cell Biol. 155:1307-1318.

Lampe, P.D., E.M. TenBroek, J.M. Burt, W.E. Kurata, R.G. Johnson, A.F. Lau (2000) Phosphorylation of connexin43 on serine 368 by protein kinase C regulates gap junctional communication. J. Cell Biol. 149:1503-12.

A.F. Paulson, P. Lampe, R.A. Meyer, E.M. TenBroek, M.M. Atkinson, T. Walseth, P. and R.G. Johnson (2000) Cyclic AMP and LDL trigger gap junction assembly through a stimulation of connexin trafficking. J. Cell Sci. 113:3037-49.

Essner, J.J., R.G. Johnson, P.B. Hackett (1999) Overexpression of thyroid hormone receptor a1 during zebrafish embryogenesis disrupts hindbrain patterning and implicates retinoic acid receptors in the control of hox gene expression. Differentiation, 65:1-11.

Krufka, A., R.G. Johnson, C.C. Wylie, and J. Heasman (1998). Evidence that dorsal-ventral differences in gap junctional communication in early Xenopus embryos are generated by b-catenin independent of all adhesion effects. Developmental Biology 200:92-102.


To view these and other publications visit http://www.ncbi.nlm.nih.gov/PubMed
search menu should say PubMed
type Johnson RG in the avaliable line

back to top


 
©2002 Regents of the University of Minnesota. All rights reserved.
Trouble seeing the text? | Contact U of M | Privacy
The University of Minnesota is an equal opportunity educator and employer.
 Last modified on Tuesday, February 7, 2006