TY - JOUR
T1 - An eIF4E-binding protein regulates katanin protein levels in C. elegans embryos
AU - Li, Wei
AU - DeBella, Leah R.
AU - Guven-Ozkan, Tugba
AU - Lin, Rueyling
AU - Rose, Lesilee S.
PY - 2009/10/5
Y1 - 2009/10/5
N2 - In Caenorhabditis elegans, the MEI-1-katanin microtubule-severing complex is required for meiosis, but must be down-regulated during the transition to embryogenesis to prevent defects in mitosis. A cullin-dependent degradation pathway for MEI-1 protein has been well documented. In this paper, we report that translational repression may also play a role in MEI-1 down-regulation. Reduction of spn-2 function results in spindle orientation defects due to ectopic MEI-1 expression during embryonic mitosis. MEL-26, which is both required for MEI-1 degradation and is itself a target of the cullin degradation pathway, is present at normal levels in spn-2 mutant embryos, suggesting that the degradation pathway is functional. Cloning of spn-2 reveals that it encodes an eIF4E-binding protein that localizes to the cytoplasm and to ribonucleoprotein particles called P granules. SPN-2 binds to the RNA-binding protein OMA-1, which in turn binds to the mei-1 3′ untranslated region. Thus, our results suggest that SPN-2 functions as an eIF4E-binding protein to negatively regulate translation of mei-1.
AB - In Caenorhabditis elegans, the MEI-1-katanin microtubule-severing complex is required for meiosis, but must be down-regulated during the transition to embryogenesis to prevent defects in mitosis. A cullin-dependent degradation pathway for MEI-1 protein has been well documented. In this paper, we report that translational repression may also play a role in MEI-1 down-regulation. Reduction of spn-2 function results in spindle orientation defects due to ectopic MEI-1 expression during embryonic mitosis. MEL-26, which is both required for MEI-1 degradation and is itself a target of the cullin degradation pathway, is present at normal levels in spn-2 mutant embryos, suggesting that the degradation pathway is functional. Cloning of spn-2 reveals that it encodes an eIF4E-binding protein that localizes to the cytoplasm and to ribonucleoprotein particles called P granules. SPN-2 binds to the RNA-binding protein OMA-1, which in turn binds to the mei-1 3′ untranslated region. Thus, our results suggest that SPN-2 functions as an eIF4E-binding protein to negatively regulate translation of mei-1.
UR - http://www.scopus.com/inward/record.url?scp=70449711342&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=70449711342&partnerID=8YFLogxK
U2 - 10.1083/jcb.200903003
DO - 10.1083/jcb.200903003
M3 - Article
C2 - 19786575
AN - SCOPUS:70449711342
SN - 0021-9525
VL - 187
SP - 33
EP - 42
JO - Journal of Cell Biology
JF - Journal of Cell Biology
IS - 1
ER -