Elomaa O, Kangas M, Sahlberg C, Tuukkanen J, Sormunen R, Liakka A, Thesleff I, Kraal G, Tryggvason K
Biocenter Oulu, University of Oulu, Finland.
Cell. 1995 Feb 24;80(4):603-9. doi: 10.1016/0092-8674(95)90514-6.
A novel murine plasma membrane protein has been identified in subpopulations of macrophages. It has an intracellular N-terminal domain, a transmembrane domain, and an extracellular region with a short spacer, an 89 Gly-Xaa-Yaa repeat-containing collagenous domain, and a C-terminal cysteine-rich domain. In situ hybridization and immunohistochemical staining have localized the protein to a subset of macrophages in the marginal zone of the spleen and the medullary cord of lymph nodes. No expression was observed in macrophages of liver or lung. Transfected COS cells synthesized a native trimeric plasma membrane protein that bound labeled bacteria and acetylated LDL, but not yeast or Ficoll. The results suggest that the novel protein is a macrophage-specific membrane receptor with a role in host defense, as it shows postnatal expression in macrophages, which are considered responsible for the binding of bacterial antigens and phagocytosis.
在巨噬细胞亚群中鉴定出一种新型小鼠质膜蛋白。它具有细胞内N端结构域、跨膜结构域和细胞外区域，该细胞外区域有一个短间隔区、一个含89个Gly-Xaa-Yaa重复序列的胶原结构域和一个C端富含半胱氨酸的结构域。原位杂交和免疫组化染色已将该蛋白定位到脾脏边缘区和淋巴结髓索中的一部分巨噬细胞。在肝脏或肺的巨噬细胞中未观察到表达。转染的COS细胞合成了一种天然三聚体质膜蛋白，该蛋白能结合标记的细菌和乙酰化低密度脂蛋白，但不能结合酵母或菲可（Ficoll）。结果表明，这种新型蛋白是一种巨噬细胞特异性膜受体，在宿主防御中起作用，因为它在巨噬细胞中呈出生后表达，而巨噬细胞被认为负责细菌抗原的结合和吞噬作用。
