Lee Sung-Jin, So In-Seop, Park Seung-Yoon, Kim In-San
Cell and Matrix Research Institute, Department of Biochemistry and Cell Biology, School of Medicine, Kyungpook National University, Daegu, Republic of Korea.
FEBS Lett. 2008 Jun 25;582(15):2161-6. doi: 10.1016/j.febslet.2008.03.058. Epub 2008 Jun 2.
Stabilin-2 was recently identified as a novel receptor for membrane phosphatidylserine of apoptotic cells. To identify proteins that were candidates for stabilin-2 cytoplasmic domain binding, we screened a human spleen cDNA library using the yeast two-hybrid system. We found that thymosin beta4 interacts with the stabilin-2 cytoplasmic domain and is co-localized with stabilin-2 at the phagocytic cup. Knockdown of thymosin beta4 significantly decreased the phagocytic activity of stabilin-2, whereas overexpression of thymosin beta4 increased this activity. Additionally, amino acids 2504-2514 of stabilin-2 cytoplasmic domain were found to be responsible for the interaction with thymosin beta4. Taken together, these results suggest that thymosin beta4 is a downstream molecule of stabilin-2 that plays a role in stabilin-2-mediated cell corpse clearance.
稳定素-2最近被鉴定为凋亡细胞膜磷脂酰丝氨酸的一种新型受体。为了鉴定作为稳定素-2细胞质结构域结合候选蛋白的蛋白质，我们使用酵母双杂交系统筛选了人脾脏cDNA文库。我们发现胸腺素β4与稳定素-2细胞质结构域相互作用，并与稳定素-2共定位于吞噬杯。敲低胸腺素β4显著降低了稳定素-2的吞噬活性，而胸腺素β4的过表达则增加了这种活性。此外，发现稳定素-2细胞质结构域的2504-2514位氨基酸负责与胸腺素β4的相互作用。综上所述，这些结果表明胸腺素β4是稳定素-2的下游分子，在稳定素-2介导的细胞尸体清除中发挥作用。
