Insights into the dynamic properties of keratin intermediate filaments in living epithelial cells

Kyeong Han Yoon, Miri Yoon, Robert D. Moir, Satya Khuon, Frederick W. Flitney, Robert D. Goldman*

*Corresponding author for this work

Research output: Contribution to journalArticle

127 Scopus citations

Abstract

The properties of keratin intermediate filaments (IFs) have been studied after transfection with green fluorescent protein (GFP)-tagged K18 and/or K8 (type I/II IF proteins). GFP-K8 and -K18 become incorporated into tonofibrils, which are comprised of bundles of keratin IFs. These tonofibrils exhibit a remarkably wide range of motile and dynamic activities. Fluorescence recovery after photobleaching (FRAP) analyses show that they recover their fluorescence slowly with a recovery t1/2 of ̃100 min. The movements of bleach zones during recovery show that closely spaced tonofibrils (< μ apart) often move at different rates and in different directions. Individual tonofibrils frequently change their shapes, and in some cases these changes appear as propagated waveforms along their long axes. In addition, short fibrils, termed keratin squiggles, are seen at the cell periphery where they move mainly towards the cell center. The motile properties of keratin IFs are also compared with those of type III IFs (vimentin) in PtK2 cells. Intriguingly, the dynamic properties of keratin tonofibrils and squiggles are dramatically different from those of vimentin fibrils and squiggles within the same cytoplasmic regions. This suggests that there are different factors regulating the dynamic properties of different types of IFs within the same cytoplasmic regions.

Original languageEnglish (US)
Pages (from-to)503-516
Number of pages14
JournalJournal of Cell Biology
Volume152
Issue number3
DOIs
StatePublished - Feb 5 2001

Keywords

  • Dynamics
  • Keratin
  • Motility
  • Squiggles
  • Tonofibrils

ASJC Scopus subject areas

  • Cell Biology

Fingerprint Dive into the research topics of 'Insights into the dynamic properties of keratin intermediate filaments in living epithelial cells'. Together they form a unique fingerprint.

  • Cite this