Shin H S, Drysdale B E, Shin M L, Noble P W, Fisher S N, Paznekas W A
Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205.
Mol Cell Biol. 1994 May;14(5):2914-25. doi: 10.1128/mcb.14.5.2914-2925.1994.
Macrophages are stimulated by lipopolysaccharide (LPS) of gram-negative organisms. The changes in LPS-stimulated macrophages include transcriptional activation of multiple immediate-early genes, which may contribute to the natural immunity to microorganisms. We have defined by deletion and mutational analysis LPS-responsive elements (LREs) in two chemokine genes, MuRantes and crg-2, which are activated in an immediate-early manner. LRE consists of two motifs, TCAYR, which is an AP-1 half site with two flanking bases, and (A/T) (G/C)NTTYC(A/T)NTTY, which resembles in part the interferon-stimulated responsive element (ISRE). The orientation of these two motifs relative to each other in MuRantes differed from that in crg-2. These two motifs are separated by 10 and 6 nonconsensus nucleotides in the MuRantes and crg-2 LREs, respectively. Stimulation of macrophage-like RAW 264.7 cells with alpha/beta interferon did not activate MuRantes, indicating that the ISRE-like motif in MuRantes does not have ISRE activity. Upon stimulation of RAW 264.7 cells with LPS, proteins capable of binding to LRE accumulate in the nuclei as measured by electrophoretic mobility shift assay. These LRE-binding proteins include c-Jun and CREB.
巨噬细胞受到革兰氏阴性菌的脂多糖（LPS）刺激。LPS刺激的巨噬细胞中的变化包括多个即刻早期基因的转录激活，这可能有助于对微生物的天然免疫。我们通过缺失和突变分析确定了两个趋化因子基因MuRantes和crg - 2中的LPS反应元件（LREs），它们以即刻早期的方式被激活。LRE由两个基序组成，TCAYR，它是一个带有两个侧翼碱基的AP - 1半位点，以及(A/T)(G/C)NTTYC(A/T)NTTY，它部分类似于干扰素刺激反应元件（ISRE）。这两个基序在MuRantes中相对于彼此的方向与在crg - 2中不同。在MuRantes和crg - 2的LREs中，这两个基序分别被10个和6个非保守核苷酸隔开。用α/β干扰素刺激巨噬细胞样RAW 264.7细胞不会激活MuRantes，这表明MuRantes中类似ISRE的基序不具有ISRE活性。在用LPS刺激RAW 264.7细胞后，通过电泳迁移率变动分析测量，能够与LRE结合的蛋白质在细胞核中积累。这些LRE结合蛋白包括c - Jun和CREB。
