Shen W J, Sridhar K, Bernlohr D A, Kraemer F B
Division of Endocrinology, Department of Medicine, Stanford University, Stanford, CA 94305-5103, USA.
Proc Natl Acad Sci U S A. 1999 May 11;96(10):5528-32. doi: 10.1073/pnas.96.10.5528.
Hormone-sensitive lipase (HSL) is a cytosolic neutral lipase that functions as the rate-limiting enzyme for the mobilization of free fatty acids in adipose tissue. By using the yeast two-hybrid system to examine the potential interaction of HSL with other cellular proteins, evidence is provided to demonstrate a direct interaction of HSL with adipocyte lipid-binding protein (ALBP), a member of the family of intracellular lipid-binding proteins that binds fatty acids, retinoids, and other hydrophobic ligands. The interaction was demonstrated in vitro by the binding of ALBP to HSL translated in vitro, to HSL in extracts of HSL overexpressing Chinese hamster ovary (CHO) cells, and to HSL in extracts of rat adipose tissue. Finally, the presence of ALBP was documented in immune complexes from rat adipose tissue immunoprecipitated with anti-HSL antibodies. The HSL-ALBP interaction was mapped to an N-terminal 300-aa region of HSL that is distinct from the C-terminal catalytic domain. These results suggest that HSL-derived fatty acids are bound by ALBP to facilitate intracellular trafficking of hydrophobic lipids.
激素敏感性脂肪酶（HSL）是一种胞质中性脂肪酶，在脂肪组织中作为游离脂肪酸动员的限速酶发挥作用。通过利用酵母双杂交系统检测HSL与其他细胞蛋白的潜在相互作用，有证据表明HSL与脂肪细胞脂质结合蛋白（ALBP）存在直接相互作用，ALBP是细胞内脂质结合蛋白家族的一员，可结合脂肪酸、类视黄醇和其他疏水配体。这种相互作用在体外通过ALBP与体外翻译的HSL、过表达HSL的中国仓鼠卵巢（CHO）细胞提取物中的HSL以及大鼠脂肪组织提取物中的HSL结合得以证实。最后，在用抗HSL抗体免疫沉淀的大鼠脂肪组织免疫复合物中记录到了ALBP的存在。HSL与ALBP的相互作用定位于HSL的N端300个氨基酸区域，该区域与C端催化结构域不同。这些结果表明，HSL衍生的脂肪酸被ALBP结合，以促进疏水脂质的细胞内运输。
