5‐Aminolevulinic acid (ALA) is the first precursor of heme biosynthesis pathway. The exogenous addition of ALA to cells leads to protoporphyrin IX (PPIX) accumulation that has been exploited in photodynamic diagnostic and photodynamic therapy. Several types of ALA transporters have been described depending on the cell type, but there was no clear entry pathway for erythroid cells. The 18 kDa translocator protein (TSPO) has been proposed to be involved in the transport of porphyrins and heme analogs.

中文翻译：

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TSPO2 将 5-氨基乙酰丙酸转运到人红白血病细胞中

5-氨基乙酰丙酸（ALA）是血红素生物合成途径的第一个前体。将 ALA 外源性添加到细胞中会导致原卟啉 IX (PPIX) 积累，这已被用于光动力诊断和光动力治疗。已经根据细胞类型描述了几种类型的 ALA 转运蛋白，但没有明确的红细胞进入途径。已提出 18 kDa 转运蛋白 (TSPO) 参与卟啉和血红素类似物的转运。