Human EML4, a novel member of the EMAP family, is essential for microtubule formation.
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Human EML4, a novel member of the EMAP family, is essential for microtubule formation. / Pollmann, Marc; Parwaresch, Reza; Adam-Klages, Sabine; Kruse, Marie-Luise; Buck, Friedrich; Heidebrecht, Hans-Juergen.
In: EXP CELL RES, Vol. 312, No. 17, 17, 2006, p. 3241-3251.Research output: SCORING: Contribution to journal › SCORING: Journal article › Research › peer-review
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T1 - Human EML4, a novel member of the EMAP family, is essential for microtubule formation.
AU - Pollmann, Marc
AU - Parwaresch, Reza
AU - Adam-Klages, Sabine
AU - Kruse, Marie-Luise
AU - Buck, Friedrich
AU - Heidebrecht, Hans-Juergen
PY - 2006
Y1 - 2006
N2 - Human EML4 (EMAP-like protein 4) is a novel microtubule-associated WD-repeat protein of 120 kDa molecular weight, which is classified as belonging to the conserved family of EMAP-like proteins. Cosedimentation assays demonstrated that EML4 associates with in vitro polymerized microtubules. Correspondingly, immunofluorescence stainings and transient expression of EGFP-labeled EML4 revealed a complete colocalization of EML4 with the interphase microtubule array of HeLa cells. We present evidence that the amino-terminal portion of EML4 (amino acids 1-249) is essential for the association with microtubules. Immunoprecipitation experiments revealed that EML4 is hyperphosphorylated on serine/threonine residues during mitosis. In addition, immunofluorescence stainings demonstrated that hyperphosphorylated EML4 is associated with the mitotic spindle, suggesting that the function of EML4 is regulated by phosphorylation. siRNA-mediated knockdown of EML4 in HeLa cells led to a significant decrease in the number of cells. In no case mitotic figures could be observed in EML4 negative HeLa cells. Additionally, we observed a significant reduction of the proliferation rate and the uptake of radioactive [3H]-thymidine as a result of EML4 silencing. Most importantly, EML4 negative cells showed a completely modified microtubule network, indicating that EML4 is necessary for correct microtubule formation.
AB - Human EML4 (EMAP-like protein 4) is a novel microtubule-associated WD-repeat protein of 120 kDa molecular weight, which is classified as belonging to the conserved family of EMAP-like proteins. Cosedimentation assays demonstrated that EML4 associates with in vitro polymerized microtubules. Correspondingly, immunofluorescence stainings and transient expression of EGFP-labeled EML4 revealed a complete colocalization of EML4 with the interphase microtubule array of HeLa cells. We present evidence that the amino-terminal portion of EML4 (amino acids 1-249) is essential for the association with microtubules. Immunoprecipitation experiments revealed that EML4 is hyperphosphorylated on serine/threonine residues during mitosis. In addition, immunofluorescence stainings demonstrated that hyperphosphorylated EML4 is associated with the mitotic spindle, suggesting that the function of EML4 is regulated by phosphorylation. siRNA-mediated knockdown of EML4 in HeLa cells led to a significant decrease in the number of cells. In no case mitotic figures could be observed in EML4 negative HeLa cells. Additionally, we observed a significant reduction of the proliferation rate and the uptake of radioactive [3H]-thymidine as a result of EML4 silencing. Most importantly, EML4 negative cells showed a completely modified microtubule network, indicating that EML4 is necessary for correct microtubule formation.
M3 - SCORING: Zeitschriftenaufsatz
VL - 312
SP - 3241
EP - 3251
JO - EXP CELL RES
JF - EXP CELL RES
SN - 0014-4827
IS - 17
M1 - 17
ER -