Emans N, Nzala N N, Desjardins M
Département d'anatomie, Faculté de médecine, Université de Montréal, Québec, Canada.
FEBS Lett. 1996 Nov 25;398(1):37-42. doi: 10.1016/s0014-5793(96)01213-6.
Phagolysosome biogenesis is driven by a series of interactions between phagosomes and organelles of the biosynthetic and endocytic pathways. The presence of endocytic markers on phagosomes suggests that phagosomes and endosomes share common structural and functional characteristics. In that line of thought, protein phosphorylation has been shown to be involved in regulatory aspects of the fusion properties of endosomes and other vacuolar organelles. To study further the mechanisms involved in phagolysosome biogenesis, we have investigated the presence of phagosome proteins that can be phosphorylated in vitro by endogenous phagosome-associated kinases. The results obtained show that proteins phosphorylated on tyrosine residues are present on phagosomes. Moreover, complex phosphorylation/dephosphorylation cycles appear to occur during phagolysosome biogenesis. The addition of endosome fractions to phagosomes inhibit the phosphorylation of phagosome proteins. These results suggest that phosphorylation and dephosphorylation events could play roles in the biogenesis of phagolysosomes and regulate, in part, the complex in vivo interactions between phagosomes and endosomes.
吞噬溶酶体的生物发生是由吞噬体与生物合成和内吞途径的细胞器之间的一系列相互作用驱动的。吞噬体上存在内吞标记物表明吞噬体和内体具有共同的结构和功能特征。按照这一思路，蛋白质磷酸化已被证明参与内体和其他液泡细胞器融合特性的调节方面。为了进一步研究吞噬溶酶体生物发生所涉及的机制，我们研究了可被内源性吞噬体相关激酶在体外磷酸化的吞噬体蛋白的存在情况。获得的结果表明，酪氨酸残基磷酸化的蛋白质存在于吞噬体上。此外，在吞噬溶酶体生物发生过程中似乎会出现复杂的磷酸化/去磷酸化循环。向内体部分添加到吞噬体中会抑制吞噬体蛋白的磷酸化。这些结果表明，磷酸化和去磷酸化事件可能在吞噬溶酶体的生物发生中起作用，并部分调节吞噬体和内体之间复杂的体内相互作用。
