Nucleoplasmic calcium regulates cell proliferation through legumain.
Nucleoplasmic calcium regulates cell proliferation through legumain.
复制标题
DOI：
10.1016/j.jhep.2010.12.022
复制
发表时间：
2011-09
影响因子：
25.7
通讯作者：
Leite F
中科院分区：
文献类型：
--
作者：
Andrade V;Guerra M;Jardim C;Melo F;Silva W;Ortega JM;Robert M;Nathanson MH;Leite F
核质Ca2+调节肝脏细胞的生长，但这种情况发生的蛋白质是未知的。我们使用快速减法杂交（RaSH）从表达核靶向PV的突变形式的细胞中减去表达Ca2+缓冲蛋白小白蛋白（PV）靶向细胞核的SKHep1肝细胞中的基因，这些突变形式的核靶向PV具有两个Ca2+结合位点失活中的一个。减法允许选择表达受核Ca2+浓度小变化影响的基因。筛选出了豆科天冬酰胺内肽酶（LGMN）。当Ca2+在SKHep1细胞的细胞核中被缓冲时，LGMN mRNA的表达减少了97%，部分是通过转录机制，免疫印迹和免疫荧光观察到蛋白水平上的表达减少。肝细胞生长因子治疗可增加LGMN的表达。通过BrdU摄取和有丝分裂指数测量，siRNA敲低LGMN可使SKHep1细胞的增殖降低约50%，尽管LGMN活性抑制剂不影响BrdU掺入。G2/M期细胞比例明显减少。这与细胞周期蛋白A和e的表达增加有关。此外，在相同的标本中，相对于正常肝细胞，肝癌细胞中的LGMN表达增加。这些发现提示了LGMN的新作用，并提供了核Ca2+信号部分通过调节LGMN表达来调节细胞增殖的证据。LGMN的表达增加可能参与了肝癌的发生。
Nucleoplasmic Ca2+ regulates cell growth in the liver, but the proteins through which this occurs are unknown. We used Rapid Subtraction Hybridization (RaSH) to subtract genes in SKHep1 liver cells expressing the Ca2+ buffer protein parvalbumin (PV) targeted to the nucleus, from genes in cells expressing a mutated form of nuclear-targeted PV which has one of two Ca2+-binding site inactivated. The subtraction permitted selection of genes whose expression was affected by a small alteration in nuclear Ca2+ concentration. The asparaginyl endopeptidase legumain (LGMN) was identified in this screening. When Ca2+ was buffered in the nucleus of SKHep1 cells, LGMN mRNA was decreased by 97%, in part by a transcriptional mechanism, and decreased expression at the protein level was observed by immunoblot and immunofluorescence. Treatment with Hepatocyte Growth Factor increased LGMN expression. Knockdown of LGMN by siRNA decreased proliferation of SKHep1 cells by ~50% as measured both by BrdU uptake and mitotic index, although an inhibitor of LGMN activity did not affect BrdU incorporation. A significant reduction in the fraction of cells in G2/M phase was seen as well. This was associated with increases in expression of cyclins A and E. Furthermore, LGMN expression was increased in hepatocellular carcinoma cells relative to normal hepatocytes in the same specimens. These findings suggest a new role for LGMN and provide evidence that nuclear Ca2+ signals regulate cell proliferation in part through modulation of LGMN expression. Increased expression of LGMN may be involved in liver carcinogenesis.
登录
查看更多内容
DOI：
10.1073/pnas.94.3.849
发表时间：
1997-02-04
影响因子：
11.1
作者：
Maniotis, AJ;Chen, CS;Ingber, DE
通讯作者：
Ingber, DE
影响因子：
64.8
作者：
Manoury, B;Hewitt, EW;Watts, C
通讯作者：
Watts, C
影响因子：
21.3
作者：
Echevarria, W;Leite, MF;Nathanson, MH
通讯作者：
Nathanson, MH
影响因子：
64.8
作者：
Deisseroth, K;Heist, EK;Tsien, RW
通讯作者：
Tsien, RW
影响因子：
64.5
作者：
HAJNOCZKY, G;ROBBGASPERS, LD;THOMAS, AP
通讯作者：
THOMAS, AP