Abstract
In order to form and maintain a protective barrier for photoreceptors, the retinal pigment epithelium relies on integrin signaling and related pathways to form adhesion complexes, undergo cell spreading, and establish a confluent cellular monolayer. Polyamines are multifunctional polycations that are essential for cell attachment and spreading, although their exact mechanisms of action are as yet unclear. We report new immunocytochemical evidence suggesting that in the cells of retinal pigment epithelium and also the intestinal epithelium, polyamines are present in a population of intracellular vesicles that appear transiently during initial stages of cell spreading. In newly attached cells with minimal spreading, the vesicles are seen near the nucleus, whereas in more highly spread cells, the vesicles are localized to the plasma membrane, near, but not precisely co-localized with an enzyme marker for adhesion complexes, focal adhesion kinase. We also observe pronounced nuclear staining in newly attached cells that have not spread, whereas this staining is decreased in cells that have spread. Nuclear staining has been previously reported in other cell types and has been attributed to DNA binding of polyamines, which is known to...Continue Reading
References
Apr 1, 1977·Journal of Biochemistry·K IgarashiS Hirose
Jan 1, 1979·Advances in Virus Research·S S Cohen, F P McCormick
Jan 3, 1975·Nature·I Flink, D E Pettijohn
Jan 29, 1976·Nature·L C Gosule, J A Schellman
Nov 1, 1992·The Journal of Cell Biology·K BurridgeL H Romer
Aug 7, 1992·Cell·A J Ridley, A Hall
Aug 7, 1992·Cell·A J RidleyA Hall
Jan 1, 1991·Annual Review of Physiology·J A Cooper
Jan 1, 1987·The Biochemical Journal·A E PeggL Wiest
Jan 1, 1988·Advances in Enzyme Regulation·A E PeggA Pajunen
Mar 1, 1987·Survey of Ophthalmology·R W Young
Jan 1, 1994·Biochemistry and Cell Biology = Biochimie Et Biologie Cellulaire·A Moszczynska, M Opas
Sep 1, 1994·The American Journal of Physiology·S A McCormackL R Johnson
Apr 7, 1995·Cell·C D Nobes, A Hall
Sep 1, 1994·The American Journal of Physiology·S A McCormackL R Johnson
Feb 1, 1993·The American Journal of Physiology·S A McCormackL R Johnson
Jun 15, 1996·The Journal of Clinical Investigation·T WangD Valle
Feb 1, 1996·Experimental Eye Research·K C DunnL M Hjelmeland
Jun 1, 1996·Hybridoma·J G DelcrosJ P Moulinoux
Aug 1, 1997·The International Journal of Biochemistry & Cell Biology·J L Guan
Feb 12, 1998·The American Journal of Physiology·S A McCormackL R Johnson
May 22, 1998·Molecular Biology of the Cell·S YamashiroF Matsumura
Feb 10, 1999·The American Journal of Physiology·S A McCormackL R Johnson
Jun 23, 1999·Molecular Immunology·N BouilléJ G Delcros
Aug 14, 1999·Science·F G Giancotti, E Ruoslahti
Feb 9, 2000·American Journal of Physiology. Cell Physiology·L M PfefferL R Johnson
May 18, 2000·Biochemical and Biophysical Research Communications·K Igarashi, K Kashiwagi
Dec 15, 2000·Oncogene·J T ParsonsS A Weed
Jul 10, 2001·American Journal of Physiology. Cell Physiology·R M RayL R Johnson
Aug 9, 2001·Neoplasia : an International Journal for Oncology Research·V G BruntonM C Frame
Feb 8, 2003·The Journal of Biological Chemistry·Ramesh M RayLeonard R Johnson