The protein synthesis inhibitor blasticidin s enters mammalian cells via leucine-rich repeat-containing protein 8D.
Leucine-rich repeat-containing 8 (LRRC8) proteins have been identified as putative receptors involved in lymphocyte development and adipocyte differentiation. They remain poorly characterized, and no specific function has been assigned to them. There is no consensus on how this family of proteins might function because homology searches suggest that members of the LRRC8 family act not as plasma membrane receptors, but rather as channels that mediate cell-cell signaling. Here we provide experimental evidence that supports a role for LRRC8s in the transport of small molecules. We show that LRRC8D is a mammalian protein required for the import of the antibiotic blasticidin S. We characterize localization and topology of LRRC8A and LRRC8D and demonstrate that LRRC8D interacts with LRRC8A, LRRC8B, and LRRC8C. Given the suggested involvement in solute transport, our results support a model in which LRRC8s form one or more complexes that may mediate cell-cell communication by transporting small solutes.
From the Whitehead Institute for Biomedical Research, Cambridge, Massachusetts 02142, the Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139.
Clarissa C
CC
Lee
From the Whitehead Institute for Biomedical Research, Cambridge, Massachusetts 02142.
Elizaveta
E
Freinkman
From the Whitehead Institute for Biomedical Research, Cambridge, Massachusetts 02142, the Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, the David H. Koch Institute for Integrative Cancer Research at Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, the Broad Institute, Cambridge, Massachusetts 02142, and the Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139.
David M
DM
Sabatini
From the Whitehead Institute for Biomedical Research, Cambridge, Massachusetts 02142, the Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, ploegh@wi.mit.edu.
Hidde L
HL
Ploegh
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001692:Biological Transport; D045744:Cell Line, Tumor; D006801:Humans; D008565:Membrane Proteins / Q000378:metabolism*; D009705:Nucleosides / Q000494:pharmacology; D011485:Protein Binding; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology*
D000900:Anti-Bacterial Agents; C485976:LRRC8A protein, human; C000589080:LRRC8A protein, mouse; D008565:Membrane Proteins; D009705:Nucleosides; D011500:Protein Synthesis Inhibitors; C004500:blasticidin S
Antibiotics; Blasticidin S; Drug Transport; Gene Knockout; LRRC8D; Mass Spectrometry (MS); Membrane Protein; Metabolomics; Protein-Protein Interaction; Somatic Cell Genetics