Delineating domains and functions of NUP98 contributing to the leukemogenic activity of NUP98-HOX fusions
LEUKEMIA RESEARCH
Authors: Yung, Eric; Sekulovic, Sanja; Argiropoulos, Bob; Lai, Courteney K.; Leung, Malina; Berg, Tobias; Vollett, Sarah; Chang, Vicky Chi-Dan; Wan, Adrian; Wong, Sandy; Humphries, R. Keith
Abstract
To determine the contribution of the common N-terminal truncation of NUP98 in NUP98-translocations resulting in acute myeloid leukemia, we have conducted a structure-function analysis of NUP98 in the context of NUP98-HOXA10HD, a novel, canonical NUP98-Hox fusion that significantly enhances the self-renewal capacity of hematopoietic stem cells and collaborates with Meis1 to induce AML in our mouse models. Our results identify that NUP98 functions by transcriptional activation likely by recruitment of CBP/p300 via its FG/GLFG repeats. In contrast, the functional interaction of NUP98 with Rae1 or the anaphase promoting complex appears non-essential for its role in NUP98-leukemogenic fusions. (c) 2010 Elsevier Ltd. All rights reserved.
Inappropriate recruitment and activity by the src homology region 2 domain-containing phosphatase 1 (SHP1) is responsible for receptor dominance in the SHIP-deficient NK cell
JOURNAL OF IMMUNOLOGY
Authors: Wahle, Joseph A.; Paraiso, Kim H. T.; Kendig, Robert D.; Lawrence, Harshani R.; Chen, Liwei; Wu, Jerry; Kerr, William G.
Abstract
We have previously demonstrated that the NKR repertoire is profoundly disrupted by SHIP deficiency. This repertoire disruption is characterized by receptor dominance where inhibitory signals from 2134 repress killing of complex targets expressing MHC class I and activating ligands. In this study, we examine the molecular basis of receptor dominance in SHIP-/- NK cells. In this study, we show that in SHIP-/- NK cells there is a pronounced bias toward the 2134 long isoform. We have also characterized signaling molecules recruited to 2134 in SHIP-/- NK cells. Interestingly, we find that similar to 10- to 16-fold more Src homology region 2 domain-containing phosphatase 1 (SHP1) is recruited to 2B4 in SHIP-/- NK cells when compared with wild type. Consistent with SHP1 overrecruitment, treatment with sodium orthovanadate or a novel inhibitor with micromolar activity against SHP1 restores the ability of SHIP-/- NK cells to kill Rae1(+) RMA and M157(+) targets. These findings define the molecular basis for hyporesponsiveness by SHIP-deficient NK cells.