TMEM175 Knockout COS1 Cell Line

TMEM175 Knockout COS1 Cell Line is a CRISPR/Cas9-edited knockout cell line generated from the COS1 host background via CRISPR/Cas9-mediated disruption of the TMEM175 gene. This engineered model provides a stable, heritable loss-of-function system for investigating TMEM175-dependent cellular processes. The knockout cell line is designed to support reproducible experiments in lysosomal biology, ion channel research, and neurodegenerative disease modeling without the need for transient suppression approaches.

COS1 cells originate from the kidney of the African green monkey (Cercopithecus aethiops) and were immortalized by SV40 transformation, yielding a fibroblast-like line with exceptional transfection efficiency and robust growth characteristics. Their permissiveness for SV40 large T antigen facilitates episomal replication of plasmids containing the SV40 origin, making COS1 cells a favored host for recombinant protein expression, functional complementation assays, and CRISPR-based genome editing. The stable, adherent phenotype and well-characterized physiology provide a reliable platform for studying membrane transport, signaling, and organellar functions.

TMEM175 encodes a lysosomal potassium channel that mediates K+ efflux, counterbalancing the electrogenic V-ATPase complex to maintain luminal acidification and protease activity. Regulated by mTORC1 and amino acid availability, TMEM175 modulates lysosomal pH, cathepsin activity, and autophagic flux. It functionally interacts with the V-ATPase complex and the LAMTOR1-4 scaffold, linking nutrient sensing to lysosomal degradation. Disruption of TMEM175 impairs mTORC1 signaling dynamics, reduces TFEB-mediated lysosomal biogenesis, and compromises mitochondrial quality control, thereby elevating Parkinson’s disease susceptibility. Within the lysosomal ion network, TMEM175 cooperates with CLC7, TPC2, and TRPML1.

In the COS1 kidney fibroblast background, the TMEM175 knockout provides a relevant context for lysosomal channel studies. COS1’s high transfection efficiency allows rescue experiments with wild-type or mutant TMEM175 and expression of genetically encoded sensors for lysosomal pH and autophagic flux. As a non-neuronal line, COS1 reflects systemic lysosomal dysfunction that mirrors metabolic and signaling perturbations in neurodegenerative diseases, making this model useful for mechanistic studies and drug screening.

This knockout cell line supports many functional assays, including LysoSensor-based lysosomal pH measurement, cathepsin activity assays, LC3 turnover monitoring, phospho-S6K western blotting, and LAMP1 immunofluorescence. Whole-lysosome patch clamp electrophysiology and mCherry-GFP-LC3 flux analysis enable direct evaluation of ion channel properties and autophagic flux. Applications range from Parkinson’s disease mechanism investigation and mTORC1 signaling studies to drug screening for lysosomal channel modulators. For further details, please contact Ascent Research.