Loss of mfsd8 alters the secretome during Dictyostelium aggregation
Major facilitator superfamily domain-containing protein 8 (MFSD8) is a transmembrane protein that has been reported to function as a lysosomal chloride channel. In humans, homozygous mutations in MFSD8 cause a late-infantile form of neuronal ceroid lipofuscinosis (NCL) called CLN7 disease. In the so...
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Elsevier
2023-12-01
|
| Series: | European Journal of Cell Biology |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S0171933523000766 |
| _version_ | 1797526250074406912 |
|---|---|
| author | Robert J. Huber Joshua Gray William D. Kim |
| author_facet | Robert J. Huber Joshua Gray William D. Kim |
| author_sort | Robert J. Huber |
| collection | DOAJ |
| description | Major facilitator superfamily domain-containing protein 8 (MFSD8) is a transmembrane protein that has been reported to function as a lysosomal chloride channel. In humans, homozygous mutations in MFSD8 cause a late-infantile form of neuronal ceroid lipofuscinosis (NCL) called CLN7 disease. In the social amoeba Dictyostelium discoideum, Mfsd8 localizes to cytoplasmic puncta and vesicles, and regulates conserved processes during the organism’s life cycle. Here, we used D. discoideum to examine the effect of mfsd8-deficiency on the secretome during the early stages of multicellular development. Mass spectrometry revealed 61 proteins that were differentially released by cells after 4 and 8 h of starvation. Most proteins were present in increased amounts in mfsd8- conditioned buffer compared to WT indicating that loss of mfsd8 deregulates protein secretion and/or causes the release of proteins not normally secreted by WT cells. GO term enrichment analyses showed that many of the proteins aberrantly released by mfsd8- cells localize to compartments and regions of the cell associated with the endo-lysosomal and secretory pathways. Mass spectrometry also revealed proteins previously known to be impacted by the loss of mfsd8 (e.g., cathepsin D), as well as proteins that may underlie mfsd8-deficiency phenotypes during aggregation. Finally, we show that mfsd8-deficiency reduces intracellular proteasome 20S activity due to the abnormal release of at least one proteasomal subunit. Together, this study reveals the impact of mfsd8 loss on the secretome during D. discoideum aggregation and lays the foundation for follow up work that investigates the role of altered protein release in CLN7 disease. |
| first_indexed | 2024-03-10T09:27:32Z |
| format | Article |
| id | doaj.art-5f23394d979c4523995e08666c1666d7 |
| institution | Directory Open Access Journal |
| issn | 0171-9335 |
| language | English |
| last_indexed | 2024-03-10T09:27:32Z |
| publishDate | 2023-12-01 |
| publisher | Elsevier |
| record_format | Article |
| series | European Journal of Cell Biology |
| spelling | doaj.art-5f23394d979c4523995e08666c1666d72023-11-22T04:46:12ZengElsevierEuropean Journal of Cell Biology0171-93352023-12-011024151361Loss of mfsd8 alters the secretome during Dictyostelium aggregationRobert J. Huber0Joshua Gray1William D. Kim2Department of Biology, Trent University, Peterborough, Ontario, Canada; Environmental and Life Sciences Graduate Program, Trent University, Peterborough, Ontario, Canada; Correspondence to: Trent University, Department of Biology, 1600 West Bank Drive, Peterborough, Ontario K9L 0G2, Canada.Environmental and Life Sciences Graduate Program, Trent University, Peterborough, Ontario, CanadaEnvironmental and Life Sciences Graduate Program, Trent University, Peterborough, Ontario, CanadaMajor facilitator superfamily domain-containing protein 8 (MFSD8) is a transmembrane protein that has been reported to function as a lysosomal chloride channel. In humans, homozygous mutations in MFSD8 cause a late-infantile form of neuronal ceroid lipofuscinosis (NCL) called CLN7 disease. In the social amoeba Dictyostelium discoideum, Mfsd8 localizes to cytoplasmic puncta and vesicles, and regulates conserved processes during the organism’s life cycle. Here, we used D. discoideum to examine the effect of mfsd8-deficiency on the secretome during the early stages of multicellular development. Mass spectrometry revealed 61 proteins that were differentially released by cells after 4 and 8 h of starvation. Most proteins were present in increased amounts in mfsd8- conditioned buffer compared to WT indicating that loss of mfsd8 deregulates protein secretion and/or causes the release of proteins not normally secreted by WT cells. GO term enrichment analyses showed that many of the proteins aberrantly released by mfsd8- cells localize to compartments and regions of the cell associated with the endo-lysosomal and secretory pathways. Mass spectrometry also revealed proteins previously known to be impacted by the loss of mfsd8 (e.g., cathepsin D), as well as proteins that may underlie mfsd8-deficiency phenotypes during aggregation. Finally, we show that mfsd8-deficiency reduces intracellular proteasome 20S activity due to the abnormal release of at least one proteasomal subunit. Together, this study reveals the impact of mfsd8 loss on the secretome during D. discoideum aggregation and lays the foundation for follow up work that investigates the role of altered protein release in CLN7 disease.http://www.sciencedirect.com/science/article/pii/S0171933523000766Batten diseaseDictyostelium discoideumMFSD8Mass spectrometryNeuronal ceroid lipofuscinosisProteomics |
| spellingShingle | Robert J. Huber Joshua Gray William D. Kim Loss of mfsd8 alters the secretome during Dictyostelium aggregation European Journal of Cell Biology Batten disease Dictyostelium discoideum MFSD8 Mass spectrometry Neuronal ceroid lipofuscinosis Proteomics |
| title | Loss of mfsd8 alters the secretome during Dictyostelium aggregation |
| title_full | Loss of mfsd8 alters the secretome during Dictyostelium aggregation |
| title_fullStr | Loss of mfsd8 alters the secretome during Dictyostelium aggregation |
| title_full_unstemmed | Loss of mfsd8 alters the secretome during Dictyostelium aggregation |
| title_short | Loss of mfsd8 alters the secretome during Dictyostelium aggregation |
| title_sort | loss of mfsd8 alters the secretome during dictyostelium aggregation |
| topic | Batten disease Dictyostelium discoideum MFSD8 Mass spectrometry Neuronal ceroid lipofuscinosis Proteomics |
| url | http://www.sciencedirect.com/science/article/pii/S0171933523000766 |
| work_keys_str_mv | AT robertjhuber lossofmfsd8altersthesecretomeduringdictyosteliumaggregation AT joshuagray lossofmfsd8altersthesecretomeduringdictyosteliumaggregation AT williamdkim lossofmfsd8altersthesecretomeduringdictyosteliumaggregation |