TY - JOUR
T1 - Plasma membrane ghosts form differently when produced from microtubule-free tobacco BY-2 cells
AU - Collings, David A.
AU - Asada, Tetsuhiro
AU - Shibaoka, Hiroh
PY - 1999
Y1 - 1999
N2 - When lysed in an actin stabilizing buffer, protoplasts made from tobacco BY-2 suspension culture cells formed plasma membrane ghosts that retained both cortical actin and microtubules. Distinct cytoskeletal arrays occurred: the most common ghost array (type I) derived from protoplasts in interphase and had random actin and microtubules, although the alignment of the actin was dependent, at least partially, on microtubule organization. Type II ghosts were larger and more irregular in shape than type I ghosts, and were characterized by a lack of microtubules and the presence of distinctive arrays of actin bundles in concentric arcs. These ghosts derived from protoplasts lacking cortical microtubules produced when wall digestion occurred while the cells were in cell division, or from protoplasts isolated in the presence of 100 μM propyzamide. Because type II ghosts derived from protoplasts of similar size to those that give rise to type I ghosts, and because type II ghosts retained ordered actin arrays while the parent protoplasts had random cortical actin, type II ghosts apparently form differently to type I ghosts. We speculate that instead of the protoplast being sheared off to produce a round ghost, the plasma membrane tears and collapses onto the slide, ordering the actin bundles in the process. One implication of this model would be that cortical microtubules provide structural support to the plasma membrane of the protoplast so that only in their absence do the type II ghosts form.
AB - When lysed in an actin stabilizing buffer, protoplasts made from tobacco BY-2 suspension culture cells formed plasma membrane ghosts that retained both cortical actin and microtubules. Distinct cytoskeletal arrays occurred: the most common ghost array (type I) derived from protoplasts in interphase and had random actin and microtubules, although the alignment of the actin was dependent, at least partially, on microtubule organization. Type II ghosts were larger and more irregular in shape than type I ghosts, and were characterized by a lack of microtubules and the presence of distinctive arrays of actin bundles in concentric arcs. These ghosts derived from protoplasts lacking cortical microtubules produced when wall digestion occurred while the cells were in cell division, or from protoplasts isolated in the presence of 100 μM propyzamide. Because type II ghosts derived from protoplasts of similar size to those that give rise to type I ghosts, and because type II ghosts retained ordered actin arrays while the parent protoplasts had random cortical actin, type II ghosts apparently form differently to type I ghosts. We speculate that instead of the protoplast being sheared off to produce a round ghost, the plasma membrane tears and collapses onto the slide, ordering the actin bundles in the process. One implication of this model would be that cortical microtubules provide structural support to the plasma membrane of the protoplast so that only in their absence do the type II ghosts form.
KW - Actin
KW - Cytokinesis
KW - Microtubules
KW - Mitosis
KW - Plasma membrane ghost
KW - Tobacco BY-2 cells
UR - http://www.scopus.com/inward/record.url?scp=0033050102&partnerID=8YFLogxK
U2 - 10.1093/oxfordjournals.pcp.a029472
DO - 10.1093/oxfordjournals.pcp.a029472
M3 - Article
AN - SCOPUS:0033050102
SN - 0032-0781
VL - 40
SP - 36
EP - 46
JO - Plant and Cell Physiology
JF - Plant and Cell Physiology
IS - 1
ER -