TY - JOUR
T1 - Cytoplasmic ATXN7L3B interferes with nuclear functions of the SAGA deubiquitinase module
AU - Li, Wenqian
AU - Atanassov, Boyko S.
AU - Lan, Xianjiang
AU - Mohan, Ryan D.
AU - Swanson, Selene K.
AU - Farria, Aimee T.
AU - Florens, Laurence
AU - Washburn, Michael P.
AU - Workman, Jerry L.
AU - Dent, Sharon Y.R.
N1 - Publisher Copyright:
© 2016, American Society for Microbiology. All Rights Reserved.
PY - 2016
Y1 - 2016
N2 - The SAGA complex contains two enzymatic modules, which house histone acetyltransferase (HAT) and deubiquitinase (DUB) activities. USP22 is the catalytic subunit of the DUB module, but two adaptor proteins, ATXN7L3 and ENY2, are necessary for DUB activity toward histone H2Bub1 and other substrates. ATXN7L3B shares 74% identity with the N-terminal region of ATXN7L3, but the functions of ATXN7L3B are not known. Here we report that ATXN7L3B interacts with ENY2 but not other SAGA components. Even though ATXN7L3B localizes in the cytoplasm, ATXN7L3B overexpression increases H2Bub1 levels, while overexpression of ATXN7L3 decreases H2Bub1 levels. In vitro, ATXN7L3B competes with ATXN7L3 to bind ENY2, and in vivo, knockdown of ATXN7L3B leads to concomitant loss of ENY2. Unlike the ATXN7L3 DUB complex, a USP22-ATXN7L3BENY2 complex cannot deubiquitinate H2Bub1 efficiently in vitro. Moreover, ATXN7L3B knockdown inhibits migration of breast cancer cells in vitro and limits expression of ER target genes. Collectively, our studies suggest that ATXN7L3B regulates H2Bub1 levels and SAGA DUB activity through competition for ENY2 binding.
AB - The SAGA complex contains two enzymatic modules, which house histone acetyltransferase (HAT) and deubiquitinase (DUB) activities. USP22 is the catalytic subunit of the DUB module, but two adaptor proteins, ATXN7L3 and ENY2, are necessary for DUB activity toward histone H2Bub1 and other substrates. ATXN7L3B shares 74% identity with the N-terminal region of ATXN7L3, but the functions of ATXN7L3B are not known. Here we report that ATXN7L3B interacts with ENY2 but not other SAGA components. Even though ATXN7L3B localizes in the cytoplasm, ATXN7L3B overexpression increases H2Bub1 levels, while overexpression of ATXN7L3 decreases H2Bub1 levels. In vitro, ATXN7L3B competes with ATXN7L3 to bind ENY2, and in vivo, knockdown of ATXN7L3B leads to concomitant loss of ENY2. Unlike the ATXN7L3 DUB complex, a USP22-ATXN7L3BENY2 complex cannot deubiquitinate H2Bub1 efficiently in vitro. Moreover, ATXN7L3B knockdown inhibits migration of breast cancer cells in vitro and limits expression of ER target genes. Collectively, our studies suggest that ATXN7L3B regulates H2Bub1 levels and SAGA DUB activity through competition for ENY2 binding.
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U2 - 10.1128/MCB.00193-16
DO - 10.1128/MCB.00193-16
M3 - Article
C2 - 27601583
AN - SCOPUS:84995478855
SN - 0270-7306
VL - 36
SP - 2855
EP - 2866
JO - Molecular and cellular biology
JF - Molecular and cellular biology
IS - 22
ER -