TY - JOUR
T1 - The Elongin B ubiquitin homology domain. Identification of Elongin B sequences important for interaction with Elongin C
AU - Brower, Christopher S.
AU - Shilatifard, Ali
AU - Mather, Timothy
AU - Kamura, Takumi
AU - Takagi, Yuichiro
AU - Haque, Dewan
AU - Treharne, Annemarie
AU - Foundling, Stephen I.
AU - Conaway, Joan Weliky
AU - Conaway, Ronald C.
PY - 1999/5/7
Y1 - 1999/5/7
N2 - Mammalian Elongin B is a 118-amino acid protein composed of an 84-amino acid amino-terminal ubiquitin-like domain and a 34-amino acid carboxyl- terminal tail. Elongin B is found in cells as a subunit of the heterodimeric Elongin BC complex, which was originally identified as a positive regulator of RNA polymerase II elongation factor Elongin A and subsequently as a component of the multiprotein von Hippel-Lindau tumor suppressor and suppressor of cytokine signaling complexes. As part of our effort to understand how the Elongin BC complex regulates the activity of Elongin A, we are characterizing Elongin B functional domains. In this report, we show that the Elongin B ubiquitin-like domain is necessary and sufficient for interaction with Elongin C and for positive regulation of Elongin A transcriptional activity. In addition, by site-directed mutagenesis of the Elongin B ubiquitin-like domain, we identify a short Elongin B region that is important for its interaction with Elongin C. Finally, we observe that both the ubiquitin-like domain and carboxyl-terminal tail are conserved in Drosophila melanogaster and Caenorhabditis elegans Elongin B homologs that efficiently substitute for mammalian Elongin B in reconstitution of the transcriptionally active Elongin ABC complex, suggesting that the carboxyl- terminal tail performs an additional function not detected in our assays.
AB - Mammalian Elongin B is a 118-amino acid protein composed of an 84-amino acid amino-terminal ubiquitin-like domain and a 34-amino acid carboxyl- terminal tail. Elongin B is found in cells as a subunit of the heterodimeric Elongin BC complex, which was originally identified as a positive regulator of RNA polymerase II elongation factor Elongin A and subsequently as a component of the multiprotein von Hippel-Lindau tumor suppressor and suppressor of cytokine signaling complexes. As part of our effort to understand how the Elongin BC complex regulates the activity of Elongin A, we are characterizing Elongin B functional domains. In this report, we show that the Elongin B ubiquitin-like domain is necessary and sufficient for interaction with Elongin C and for positive regulation of Elongin A transcriptional activity. In addition, by site-directed mutagenesis of the Elongin B ubiquitin-like domain, we identify a short Elongin B region that is important for its interaction with Elongin C. Finally, we observe that both the ubiquitin-like domain and carboxyl-terminal tail are conserved in Drosophila melanogaster and Caenorhabditis elegans Elongin B homologs that efficiently substitute for mammalian Elongin B in reconstitution of the transcriptionally active Elongin ABC complex, suggesting that the carboxyl- terminal tail performs an additional function not detected in our assays.
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U2 - 10.1074/jbc.274.19.13629
DO - 10.1074/jbc.274.19.13629
M3 - Article
C2 - 10224134
AN - SCOPUS:0033532061
SN - 0021-9258
VL - 274
SP - 13629
EP - 13636
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 19
ER -