Stuhlsatz-Krouper S M, Bennett N E, Schaffer J E
Center for Cardiovascular Research, Department of Internal Medicine and the Department of Molecular Biology and Pharmacology, Washington University School of Medicine, St. Louis, Missouri 63110-1010, USA.
J Biol Chem. 1998 Oct 30;273(44):28642-50. doi: 10.1074/jbc.273.44.28642.
The murine fatty acid transport protein (FATP) was identified on the basis of its ability to facilitate uptake of long chain fatty acids (LCFAs) when expressed in mammalian cells. To delineate FATP domains important for transport function, we cloned the human heart FATP ortholog. Comparison of the human, murine, and yeast amino acid sequences identified a highly conserved motif, IYTSGTTGXPK, also found in a number of proteins that form adenylated intermediates. We demonstrate that depletion of intracellular ATP dramatically reduces FATP-mediated LCFA uptake. Furthermore, wild-type FATP specifically binds [alpha-32P]azido-ATP. Introduction of a serine to alanine substitution (S250A) in the IYTSGTTGXPK motif produces an appropriately expressed and metabolized mutant FATP that demonstrates diminished LCFA transport function and decreased [alpha-32P]azido-ATP binding. These results are consistent with a mechanism of action for FATP involving ATP binding that is dependent on serine 250 of the IYTSGTTGXPK motif.
鼠脂肪酸转运蛋白（FATP）是根据其在哺乳动物细胞中表达时促进长链脂肪酸（LCFA）摄取的能力而鉴定出来的。为了确定对转运功能重要的FATP结构域，我们克隆了人心脏FATP直系同源物。对人、鼠和酵母氨基酸序列的比较确定了一个高度保守的基序IYTSGTTGXPK，在许多形成腺苷酸化中间体的蛋白质中也发现了该基序。我们证明细胞内ATP的消耗会显著降低FATP介导的LCFA摄取。此外，野生型FATP特异性结合[α-32P]叠氮基ATP。在IYTSGTTGXPK基序中引入丝氨酸到丙氨酸的取代（S250A）产生了一个表达和代谢正常的突变型FATP，其表现出LCFA转运功能减弱和[α-32P]叠氮基ATP结合减少。这些结果与FATP的作用机制一致，即涉及依赖于IYTSGTTGXPK基序丝氨酸250的ATP结合。
