Abstract
Mixed lineage leukemia (MLL) is a key epigenetic regulator of normal hematopoietic development and chromosomal translocations involving MLL are one of the most common genetic alterations in human leukemia. Here we show that ASB2, a component of the ECS ASB E3 ubiquitin ligase complex, mediates MLL degradation through interaction with the PHD/Bromodomain region of MLL. Forced expression of ASB2 degrades MLL and reduces MLL transactivation activity. In contrast, the MLL-AF9 fusion protein does not interact with ASB2 and is resistant to ASB2 mediated degradation. Increased expression of ASB2 during hematopoietic differentiation is associated with decreased levels of MLL protein and down-regulation of MLL target genes. Knockdown of ASB2 leads to increased expression of HOXA9 and delayed cell differentiation. Our data support a model whereby ASB2 contributes to hematopoietic differentiation, in part, through MLL degradation and HOX gene down-regulation. Moreover, deletion of the PHD/Bromo region renders MLL fusion proteins resistant to ASB2-mediated degradation and may contribute to leukemogenesis.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1151-1161 |
| Number of pages | 11 |
| Journal | Blood |
| Volume | 119 |
| Issue number | 5 |
| DOIs | |
| State | Published - Feb 2 2012 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Hematology
- Biochemistry
- Cell Biology
- Immunology
Cite this
ECS ASB2 mediates MLL degradation during hematopoietic differentiation. / Wang, Jingya; Muntean, Andrew G.; Hess, Jay.
In: Blood, Vol. 119, No. 5, 02.02.2012, p. 1151-1161.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - ECS ASB2 mediates MLL degradation during hematopoietic differentiation
AU - Wang, Jingya
AU - Muntean, Andrew G.
AU - Hess, Jay
PY - 2012/2/2
Y1 - 2012/2/2
N2 - Mixed lineage leukemia (MLL) is a key epigenetic regulator of normal hematopoietic development and chromosomal translocations involving MLL are one of the most common genetic alterations in human leukemia. Here we show that ASB2, a component of the ECS ASB E3 ubiquitin ligase complex, mediates MLL degradation through interaction with the PHD/Bromodomain region of MLL. Forced expression of ASB2 degrades MLL and reduces MLL transactivation activity. In contrast, the MLL-AF9 fusion protein does not interact with ASB2 and is resistant to ASB2 mediated degradation. Increased expression of ASB2 during hematopoietic differentiation is associated with decreased levels of MLL protein and down-regulation of MLL target genes. Knockdown of ASB2 leads to increased expression of HOXA9 and delayed cell differentiation. Our data support a model whereby ASB2 contributes to hematopoietic differentiation, in part, through MLL degradation and HOX gene down-regulation. Moreover, deletion of the PHD/Bromo region renders MLL fusion proteins resistant to ASB2-mediated degradation and may contribute to leukemogenesis.
AB - Mixed lineage leukemia (MLL) is a key epigenetic regulator of normal hematopoietic development and chromosomal translocations involving MLL are one of the most common genetic alterations in human leukemia. Here we show that ASB2, a component of the ECS ASB E3 ubiquitin ligase complex, mediates MLL degradation through interaction with the PHD/Bromodomain region of MLL. Forced expression of ASB2 degrades MLL and reduces MLL transactivation activity. In contrast, the MLL-AF9 fusion protein does not interact with ASB2 and is resistant to ASB2 mediated degradation. Increased expression of ASB2 during hematopoietic differentiation is associated with decreased levels of MLL protein and down-regulation of MLL target genes. Knockdown of ASB2 leads to increased expression of HOXA9 and delayed cell differentiation. Our data support a model whereby ASB2 contributes to hematopoietic differentiation, in part, through MLL degradation and HOX gene down-regulation. Moreover, deletion of the PHD/Bromo region renders MLL fusion proteins resistant to ASB2-mediated degradation and may contribute to leukemogenesis.
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U2 - 10.1182/blood-2011-06-362079
DO - 10.1182/blood-2011-06-362079
M3 - Article
VL - 119
SP - 1151
EP - 1161
JO - Blood
JF - Blood
SN - 0006-4971
IS - 5
ER -