Evolutional insights into the interaction between Rab7 and RILP in lysosome motility
Gaofeng Cui,
Zhiyan Jiang,
Yaoyao Chen,
Yun Li,
Shupei Ai,
Ranran Sun,
Xin Yi,
Guohua Zhong
Affiliations
Gaofeng Cui
College of Plant Protection, South China Agricultural University, Guangzhou 510642, China; Guangdong Provincial Key Laboratory of Silviculture, Protection and Utilization, Guangdong Academy of Forestry, Guangzhou 510520, China
Zhiyan Jiang
College of Plant Protection, South China Agricultural University, Guangzhou 510642, China
Yaoyao Chen
College of Plant Protection, South China Agricultural University, Guangzhou 510642, China
Yun Li
College of Plant Protection, South China Agricultural University, Guangzhou 510642, China
Shupei Ai
College of Plant Protection, South China Agricultural University, Guangzhou 510642, China
Ranran Sun
College of Plant Protection, South China Agricultural University, Guangzhou 510642, China
Xin Yi
College of Plant Protection, South China Agricultural University, Guangzhou 510642, China
Guohua Zhong
College of Plant Protection, South China Agricultural University, Guangzhou 510642, China; Corresponding author
Summary: Lysosome motility is critical for the cellular function. However, Rab7-related transport elements showed genetic differences between vertebrates and invertebrates, making the mechanism of lysosomal motility mysterious. We suggested that Rab7 interacted with RILP as a feature of highly evolved organisms since they could interact with each other in Spodoptera frugiperda but not in Drosophila melanogaster. The N-terminus of Sf-RILP was identified to be necessary for their interaction, and Glu61 was supposed to be the key point for the stability of the interaction. A GC-rich domain on the C-terminal parts of Sf-RILP hampered the expression of Sf-RILP and its interaction with Sf-Rab7. Although the corresponding vital amino acids in the mammalian model at the C-terminus of Sf-RILP turned to be neutral, the C-terminus would also help with the homologous interactions between RILP fragments in insects. The significantly different interactions in invertebrates shed light on the biodiversity and complexity of lysosomal motility.
