Both RNA-Binding Domains in Heterogeneous Nuclear Ribonucleoprotein A1 Contribute Toward Single-Stranded-RNA Binding

Biochemistry ◽  
1994 ◽  
Vol 33 (27) ◽  
pp. 8272-8281 ◽  
Author(s):  
Yousif Shamoo ◽  
Norzehan Abdul-Manan ◽  
Ann M. Patten ◽  
Janet K. Crawford ◽  
Matthew C. Pellegrini ◽  
...  



2000 ◽  
Vol 348 (1) ◽  
pp. 151-158 ◽  
Author(s):  
Mate TOLNAY ◽  
Lajos BARANYI ◽  
George C. TSOKOS

Heterogeneous nuclear ribonucleoprotein D0 (hnRNP D0) is an abundant, ubiquitous protein that binds RNA and DNA sequences specifically, and has been implicated in the transcriptional regulation of the human complement receptor 2 gene. We found that in vivo expression of hnRNP D0-GAL4 fusion proteins increased the transcriptional activity of a GAL4-driven reporter gene, providing direct proof that hnRNP D0 possesses a transactivator domain. We found, using truncated hnRNP D0 proteins fused to GAL4, that 29 amino acids in the N-terminal region are critical for transactivation. We established, using a series of recombinant truncated hnRNP D0 proteins, that the tandem RNA-binding domains alone were not able to bind double-stranded DNA. Nevertheless, 24 additional amino acids of the C-terminus imparted sequence-specific DNA binding. Experiments using peptide-specific antisera supported the importance of the 24-amino-acid region in DNA binding, and suggested the involvement of the 19-amino-acid alternative insert which is present in isoforms B and D. The N-terminus had an inhibitory effect on binding of hnRNP D0 to single-stranded, but not to double-stranded, DNA. Although both recombinant hnRNP D0B and D0D bound DNA, only the B isoform recognized DNA in vivo. We propose that the B isoform of hnRNP D0 functions in the nucleus as a DNA-binding transactivator and has distinct transactivator and DNA-binding domains.



Genetics ◽  
2001 ◽  
Vol 159 (4) ◽  
pp. 1617-1630
Author(s):  
Suk-Won Jin ◽  
Nancy Arno ◽  
Adam Cohen ◽  
Amy Shah ◽  
Qijin Xu ◽  
...  

Abstract FOG-1 controls germ cell fates in the nematode Caenorhabditis elegans. Sequence analyses revealed that FOG-1 is a cytoplasmic polyadenylation element binding (CPEB) protein; similar proteins from other species have been shown to bind messenger RNAs and regulate their translation. Our analyses of fog-1 mutations indicate that each of the three RNA-binding domains of FOG-1 is essential for activity. In addition, biochemical tests show that FOG-1 is capable of binding RNA sequences in the 3′-untranslated region of its own message. Finally, genetic assays reveal that fog-1 functions zygotically, that the small fog-1 transcript has no detectable function, and that missense mutations in fog-1 cause a dominant negative phenotype. This last observation suggests that FOG-1 acts in a complex, or as a multimer, to regulate translation. On the basis of these data, we propose that FOG-1 binds RNA to regulate germ cell fates and that it does so by controlling the translation of its targets. One of these targets might be the fog-1 transcript itself.



2004 ◽  
Vol 337 (4) ◽  
pp. 799-816 ◽  
Author(s):  
Carina Johansson ◽  
L.David Finger ◽  
Lukas Trantirek ◽  
Thomas D Mueller ◽  
Soyoun Kim ◽  
...  


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