TY - JOUR
T1 - Lysosomal integral membrane protein LGP85 (LIMP-2) is ubiquitinated at the N-terminal cytoplasmic domain
AU - Fujimoto, Keiko
AU - Uchida, Shotaro
AU - Amen, Riham N.S.
AU - Ishii, Yuji
AU - Tanaka, Yoshitaka
AU - Hirota, Yuko
N1 - Funding Information:
We thank Dr. T. Chiba from Tsukuba University for providing FLAG-tag ubiquitin plasmid. We appreciate the technical support from the Research Support Center, Graduate School of Medical Sciences, Kyushu University.
Funding Information:
This research was supported in part by the Japan Society for the Promotion of Science KAKENHI Grant Number 15K19010 (YH).
Publisher Copyright:
© 2020 Elsevier Inc.
PY - 2020/4/2
Y1 - 2020/4/2
N2 - LGP85/LIMP-2 is a type III transmembrane glycoprotein of lysosomes, which traverses the membrane twice with an N-terminal uncleaved signal sequence and C-terminal hydrophobic domain. In addition to functioning as a receptor for a lysosomal enzyme β-glucocerebrosidase and for several enteroviruses, LGP85 plays a key role in the biogenesis and maintenance of endosomal/lysosomal compartments (ELCs). Our previous studies have demonstrated that overexpression of rat LGP85 into COS cells results in the enlarged ELCs, from where membrane trafficking is impaired. We show here that rat LGP85 is polyubiquitinated at the N-terminal short cytoplasmic domain that comprises of only three amino acid residues, alanine, arginine, and cysteine. Replacement of either arginine or cysteine with alanine within the N-terminal cytoplasmic domain did not influence the ubiquitination of LGP85, thereby indicating that ubiquitin (Ub) is conjugated to the α-NH2 group of the N-terminal alanine residue. Furthermore, we were able to define a domain necessary for ubiquitination in a region ranging from the amino acids 156 to 255 within the lumenal domain of LGP85. This is the first report showing that the integral lysosomal membrane protein LGP85 is ubiquitinated.
AB - LGP85/LIMP-2 is a type III transmembrane glycoprotein of lysosomes, which traverses the membrane twice with an N-terminal uncleaved signal sequence and C-terminal hydrophobic domain. In addition to functioning as a receptor for a lysosomal enzyme β-glucocerebrosidase and for several enteroviruses, LGP85 plays a key role in the biogenesis and maintenance of endosomal/lysosomal compartments (ELCs). Our previous studies have demonstrated that overexpression of rat LGP85 into COS cells results in the enlarged ELCs, from where membrane trafficking is impaired. We show here that rat LGP85 is polyubiquitinated at the N-terminal short cytoplasmic domain that comprises of only three amino acid residues, alanine, arginine, and cysteine. Replacement of either arginine or cysteine with alanine within the N-terminal cytoplasmic domain did not influence the ubiquitination of LGP85, thereby indicating that ubiquitin (Ub) is conjugated to the α-NH2 group of the N-terminal alanine residue. Furthermore, we were able to define a domain necessary for ubiquitination in a region ranging from the amino acids 156 to 255 within the lumenal domain of LGP85. This is the first report showing that the integral lysosomal membrane protein LGP85 is ubiquitinated.
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U2 - 10.1016/j.bbrc.2020.01.095
DO - 10.1016/j.bbrc.2020.01.095
M3 - Article
C2 - 32007273
AN - SCOPUS:85078528402
SN - 0006-291X
VL - 524
SP - 424
EP - 430
JO - Biochemical and Biophysical Research Communications
JF - Biochemical and Biophysical Research Communications
IS - 2
ER -