TY - JOUR
T1 - The functioning of the drosophila CPEB protein orb is regulated by phosphorylation and requires casein kinase 2 activity
AU - Wong, Li Chin
AU - Costa, Alexandre
AU - McLeod, Ian
AU - Sarkeshik, Ali
AU - Yates, John
AU - Kyin, Saw
AU - Perlman, David
AU - Schedl, Paul
PY - 2011/9/19
Y1 - 2011/9/19
N2 - The Orb CPEB protein regulates translation of localized mRNAs in Drosophila ovaries. While there are multiple hypo- and hyperphosphorylated Orb isoforms in wild type ovaries, most are missing in orb F303, which has an amino acid substitution in a buried region of the second RRM domain. Using a proteomics approach we identified a candidate Orb kinase, Casein Kinase 2 (CK2). In addition to being associated with Orb in vivo, we show that ck2 is required for orb functioning in gurken signaling and in the autoregulation of orb mRNA localization and translation. Supporting a role for ck2 in Orb phosphorylation, we find that the phosphorylation pattern is altered when ck2 activity is partially compromised. Finally, we show that the Orb hypophosphorylated isoforms are in slowly sedimenting complexes that contain the translational repressor Bruno, while the hyperphosphorylated isoforms assemble into large complexes that co-sediment with polysomes and contain the Wisp poly(A) polymerase.
AB - The Orb CPEB protein regulates translation of localized mRNAs in Drosophila ovaries. While there are multiple hypo- and hyperphosphorylated Orb isoforms in wild type ovaries, most are missing in orb F303, which has an amino acid substitution in a buried region of the second RRM domain. Using a proteomics approach we identified a candidate Orb kinase, Casein Kinase 2 (CK2). In addition to being associated with Orb in vivo, we show that ck2 is required for orb functioning in gurken signaling and in the autoregulation of orb mRNA localization and translation. Supporting a role for ck2 in Orb phosphorylation, we find that the phosphorylation pattern is altered when ck2 activity is partially compromised. Finally, we show that the Orb hypophosphorylated isoforms are in slowly sedimenting complexes that contain the translational repressor Bruno, while the hyperphosphorylated isoforms assemble into large complexes that co-sediment with polysomes and contain the Wisp poly(A) polymerase.
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U2 - 10.1371/journal.pone.0024355
DO - 10.1371/journal.pone.0024355
M3 - Article
C2 - 21949709
AN - SCOPUS:80052872258
SN - 1932-6203
VL - 6
JO - PloS one
JF - PloS one
IS - 9
M1 - e24355
ER -