Nuclear translocation of the calcium-binding protein ALG-2 induced by the RNA-binding protein RBM22.
By yeast two-hybrid screening using the calcium-binding protein ALG-2 as bait a new target of ALG-2 was identified, the RNA-binding protein RBM22. In order to confirm these interactions in vivo we prepared fluorescent constructs by using the monomeric red fluorescent protein to label ALG-2 and the enhanced green fluorescent protein to label RBM22. Confocal microscopy of NIH 3T3 cells transfected with either ALG-2 or RBM22 expression constructs encoding fluorescent fusion proteins alone revealed that the majority of ALG-2 was localized in the cytoplasm whereas RBM22 was located in the nucleus. When cells were co-transfected with expression vectors encoding both fusion proteins ALG-2 was found in the nucleus indicating that RBM22 which can shuttle between the cytoplasm and the nucleus may play a role in nuclear translocation of ALG-2. Using zebrafish as a model mRNA homologues of ALG-2 and RBM22 were microinjected into the blastodisc-yolk margin of zebrafish embryos at the 1-cell stage followed by monitoring the fusion proteins during development of the zebrafish. Hereby, we observed that ALG-2 alone evenly distributed within the cell, whereas in the presence of RBM22 the two proteins co-localized within the nucleus. More than 95% of the two proteins co-localized within the same area in the nucleus suggesting a functional interaction between the Ca(2+)-signaling protein ALG-2 and the RNA-binding protein RBM22.
Montaville
P
P
Department of NMR-based Structural Biology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany.
Dai
Y
Y
Cheung
C Y
CY
Giller
K
K
Becker
S
S
Michalak
M
M
Webb
S E
SE
Miller
A L
AL
Krebs
J
J
D021581:Active Transport, Cell Nucleus; D000595:Amino Acid Sequence; D000818:Animals; D051017:Apoptosis Regulatory Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D020013:Calcium Signaling; D002135:Calcium-Binding Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D002467:Cell Nucleus / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D041681:NIH 3T3 Cells; D016601:RNA-Binding Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D014162:Transfection; D020798:Two-Hybrid System Techniques; D015027:Zebrafish / Q000196:embryology / Q000378:metabolism
D051017:Apoptosis Regulatory Proteins; D002135:Calcium-Binding Proteins; C097753:PDCD6 protein, human; C516558:RBM22 protein, human; D016601:RNA-Binding Proteins