Phorbol ester-induced actin cytoskeletal reorganization requires a heavy metal ion, probably Zn2+.
Loading...
Date
1991-12
Authors
Hedberg, K. K.
Birrell, G. B.
Griffith, O. H.
Journal Title
Journal ISSN
Volume Title
Publisher
Cell Regulation
Abstract
The cell-permeant heavy metal chelator N,N,N',Ntetrakis(
2-pyridylmethyl)ethylenediamine (TPEN) was
found to counteract phorbol ester-induced actin
reorganization in PTK2 and Swiss 3T3 cells. By us
ing fluorescence and the higher resolution tech
nique of photoelectron microscopy to monitor actin
patterns, 15-min pretreatment with 25-50 pM TPEN
was found to dramatically reduce actin alterations
resulting from subsequent phorbol ester treatment
in PTK2 cells. Similar results were obtained with
Swiss 3T3 cells using 50 mM TPEN for 1.5 h. Phorbol
ester-induced actin alterations are thought to de
pend on activation of protein kinase C (PKC). In
contrast to the phorbol ester effect, the PKC-independent
actin cytoskeletal disruption caused by
staurosporine and cytochalasin B was unaffected
by TPEN pretreatment. TPEN did not block phorbol
ester-induced activation of PKC in Swiss 3T3 cells,
as observed by the phosphorylation of the 80K PKC
substrate protein (MARCKS protein). TPEN also did
not inhibit partially purified PKC from Swiss 3T3
cells in an in vitro PKC-specific commercial assay.
To establish that the effect of TPEN is the removal
of metal ions and not some other nonspecific effect
of TPEN, a series of transition metal ions was
added at the end of the TPEN pretreatment. The
results indicate that the transient but dramatic
phorbol ester-induced reorganization of the actin
cytoskeleton in cultured cells depends on an inter
action of PKC with a heavy metal, probably zinc.
Description
14 pages
Keywords
Citation
Hedberg, K. K. , Birrell, G. B. and Griffith, O. H. (1991) Phorbol ester-induced actin cytoskeletal reorganization requires a heavy metal ion, probably Zn2+. Cell Regulation 2, 1067-1079.