Kenny D A, Jurata L W, Saga Y, Gill G N
Department of Medicine, University of California at San Diego, La Jolla, CA 92093-0650, USA.
Proc Natl Acad Sci U S A. 1998 Sep 15;95(19):11257-62. doi: 10.1073/pnas.95.19.11257.
LMO4 is a novel member of the LIM-only (LMO) subfamily of LIM domain-containing transcription factors. LMO1, LMO2, and LMO4 have distinct expression patterns in adult tissue, and we demonstrate that nuclear retention of LMO proteins is enhanced by the nuclear LIM interactor (NLI). In situ hybridization to early mouse embryos of 8-14.5 days revealed a complex pattern of LMO4 expression spatially overlapping with NLI and LHX genes. LMO4 expression in somite is repressed in mice mutant for the segment polarity gene Mesp2 and expanded in Splotch mutants. During jaw and limb outgrowth, LMO4 and LMO2 expression define mesenchyme that is uncommitted to regional fates. Although both LMO2 and LMO4 are activated in thymic blast cells, only LMO4 is expressed in mature T cells. Mesenchymal and thymic blast cell expression patterns of LMO4 and LMO2 are consistent with the suggestion that LMO genes inhibit differentiation.
LMO4是含LIM结构域转录因子中仅含LIM(LMO)亚家族的一个新成员。LMO1、LMO2和LMO4在成体组织中有不同的表达模式,并且我们证明核LIM相互作用分子(NLI)可增强LMO蛋白的核内滞留。对8至14.5天的早期小鼠胚胎进行原位杂交显示,LMO4的表达模式复杂,在空间上与NLI和LHX基因重叠。在节段极性基因Mesp2突变的小鼠中,体节中的LMO4表达受到抑制,而在斑点突变体中则扩大。在颌骨和肢体生长过程中,LMO4和LMO2的表达界定了尚未确定区域命运的间充质。尽管LMO2和LMO4在胸腺母细胞中均被激活,但只有LMO4在成熟T细胞中表达。LMO4和LMO2在间充质和胸腺母细胞中的表达模式与LMO基因抑制分化的观点一致。