TY - JOUR
T1 - Mammalian actin binding protein 1 is essential for endocytosis but not lamellipodia formation
T2 - Functional analysis by RNA interference
AU - Mise-Omata, Setsuko
AU - Montagne, Benjamin
AU - Deckert, Marcel
AU - Wienands, Jürgen
AU - Acuto, Oreste
N1 - Funding Information:
We thank Drs. F. Michel and T. Tuschl for help with some experiments and suggestions. We also thank Drs. G. Langsley, S. Pellegrini, and F. Michel for critical reading of the manuscript. S.M.-O. was a recipient of an Association pour la Recherche sur le Cancer fellowship. This work was supported by grants from the Institut Pasteur and the Centre National pour la Recherche Scientifique.
PY - 2003/2/14
Y1 - 2003/2/14
N2 - Mammalian actin binding protein 1 (mAbp1, also called SH3P7/Hip55) is structurally and functionally related to yeast Abp1 and to cortactin, both of which have been implicated in endocytotic processes. mAbp1 associates through its SH3 domain with dynamin, a large GTPase essential for vesicle fission. To clarify the function of mAbp1, we specifically knocked down its expression in human embryonic kidney 293T cells, using RNA interference (RNAi). Co-transfection of a short interfering RNA (siRNA) together with a plasmid coding for a surface marker, followed by purification of transfected cells, enabled us to obtain a cell population having up to 90% inhibition of mAbp1 expression. In mAbp1-knocked down cells, transferrin (Tf) receptor endocytosis was significantly inhibited and intracellular distribution of the early endosomal compartment was modified. In contrast, in these cells actin and microtubule filaments appeared normal, and formation of lamellipodia induced by active Rac was not inhibited. This study provides definitive evidence that mAbp1 is indispensable for receptor-mediated endocytosis.
AB - Mammalian actin binding protein 1 (mAbp1, also called SH3P7/Hip55) is structurally and functionally related to yeast Abp1 and to cortactin, both of which have been implicated in endocytotic processes. mAbp1 associates through its SH3 domain with dynamin, a large GTPase essential for vesicle fission. To clarify the function of mAbp1, we specifically knocked down its expression in human embryonic kidney 293T cells, using RNA interference (RNAi). Co-transfection of a short interfering RNA (siRNA) together with a plasmid coding for a surface marker, followed by purification of transfected cells, enabled us to obtain a cell population having up to 90% inhibition of mAbp1 expression. In mAbp1-knocked down cells, transferrin (Tf) receptor endocytosis was significantly inhibited and intracellular distribution of the early endosomal compartment was modified. In contrast, in these cells actin and microtubule filaments appeared normal, and formation of lamellipodia induced by active Rac was not inhibited. This study provides definitive evidence that mAbp1 is indispensable for receptor-mediated endocytosis.
KW - Dynamin
KW - Lamellipodia
KW - Receptor-mediated endocytosis
KW - SH3P7
KW - mAbp1
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U2 - 10.1016/S0006-291X(02)02972-8
DO - 10.1016/S0006-291X(02)02972-8
M3 - Article
C2 - 12565838
AN - SCOPUS:0037436305
SN - 0006-291X
VL - 301
SP - 704
EP - 710
JO - Biochemical and Biophysical Research Communications
JF - Biochemical and Biophysical Research Communications
IS - 3
ER -