Apr 01, 2022

Public workspaceCell line construction and maintenance for Lyso-IP and Endo-IP analysis of amyloid precursor protein processing, version 2 V.2

  • 1Department of Cell Biology, Harvard Medical School Boston, MA 02115, USA;
  • 2Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA;
  • 3Current affiliation: Seoul National University, School of Dentistry;
  • 4Harvard Medical School
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Protocol CitationHankum Park, Frances V Hundley, Sharan Sharan Swarup, Harper JW 2022. Cell line construction and maintenance for Lyso-IP and Endo-IP analysis of amyloid precursor protein processing, version 2. protocols.io https://dx.doi.org/10.17504/protocols.io.4r3l24kxxg1y/v2Version created by Frances V Hundley
License: This is an open access protocol distributed under the terms of the Creative Commons Attribution License,  which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Protocol status: Working
We use this protocol and it’s working
Created: March 25, 2022
Last Modified: May 31, 2024
Protocol Integer ID: 59915
Keywords: ASAPCRN
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Abstract
Lyso-IP is a method that allows for the isolation of lysosomes for proteomics and metabolomics (dx.doi.org/10.17504/protocols.io.bybjpskn; dx.doi.org/10.17504/protocols.io.bx9hpr36). We have developed an analogous approach for purification of early/sorting endosomes (Endo-IP). In addition, we have found that endolysosomal purification via Lyso-IP and Endo-IP can be coupled to a quantitative proteomics workflow to obtain snapshots of Amyloid Precursor Protein (APP) processing to its Aβ products (Park et al. 2022). Here, we describe methods for cell line construction and maintenance of 293 cells with TMEM192-3xHA and 3xFLAG-EEA1, which are used for lysosome and endosome purification, respectively. of patient mutations to APP promotes processing. Cells with endogenously-tagged TMEM192 and stably expressing FLAG-EEA1 are referred to as 293EL cells, for Endo-IP and Lyso-IP. These cells were also prepared in a form that has a deletion of the APP gene (293EL APP-/-) and the same cells reconstituted with a lentivirus stably expressing a patient mutant form (APPSw;T700N) which promotes APP processing and allows functional analysis of APP processing.
Materials
ABC
REAGENT or RESOURCE SOURCE IDENTIFIER
Chemicals, peptides, and recombinant proteins
Puromycin Sigma-Aldrich P9620
G418 (Geneticin) Invivogen ant-gn-2
Dulbecco’s MEM (DMEM), high glucose, pyruvate GIBCO / Invitrogen 11995
Experimental models: Cell lines
293T cells ATCC CRL-3216
293 cells ATCC CRL-1573
293L: TMEM192-3xHA This study
293L-APP-/-: TMEM192-3xHA; APP-/- This study
293EL-APP-/-: TMEM192-3xHA; APP-/-; FLAG-EEA1 This study
293EL-APP*: TMEM192-3xHA; APP-/-; FLAG-EEA1; APPSw;T700N This study
Recombinant DNA
pSMART TMEM192-3xHA (targeting vector for genomic tagging) 35 Addgene #175777
pHAGE-FLAG-EEA1 This study Addgene #176491
pHAGE-FLAG-RAB11A This study Addgene #176489
pPHAGE-FLAG-TFR1 This study Addgene #176490
pPHAGE-FLAG-RAB5A This study Addgene #176488
pX459-gRNA-APP (for making APP deletion by CRISPR/Cas9) This study Addgene #176487
pENTR221-APP751 DNA Resource Core, Harvard Medical School HsCD00431993
pHAGE-APPSw;T700N This study Deposited in Addgene
Cell line maintenance
Cell line maintenance
Maintain 293 cells in Dulbecco’ Modifies Eagles Medium (DMEM) with 10% fetal bovine serum and optional 1% penicillin-streptomycin. Additionally, grow 293EL cells in 1.2 µg/ml puromycin and 200 µg/ml G418 to maintain selection for 3xFLAG-EEA1 and TMEM192-3XHA, respectively.
Endogenous tagging of TMEM192 with 3xHA
Endogenous tagging of TMEM192 with 3xHA
For endogenous tagging of TMEM192 with 3xHA, co-transfect 293 cells with pX459 containing a gRNA (5’-AGTAGAACGTGAGAGGCTCA) targeting adjacent to the translational termination sequence in TMEM192 and pSMART containing 5’ and 3’ homology arms for TMEM192 in which the termination codon is replaced by a 3xHA epitope sequence followed by a TAA stop codon (Addgene #175777).
Identify homozygously targeted clones by immunoblotting cell extracts with α-HA and α-TMEM192. These are referred to as 293L cells for Lyso-IP.
Stable expression of 3xFLAG-EEA1
Stable expression of 3xFLAG-EEA1
Generate puromycin-resistant pHAGE lentiviral vectors expressing EEA1 by recombining open reading frames in pENTR vectors into a pHAGE-N-3xFLAG vector.
Infect 293L cells with viral supernatants derived from transfection of 293T cells with pHAGE-3xFLAG-EEA1 vector (Addgene #176491) and appropriate packaging and envelope vectors. Select for viral integration with puromycin (1.2 µg/ml). Select a monoclonal population. These are referred to as 293EL cells for Endo-IP and Lyso-IP.
APP knock-out
APP knock-out
For APP knock-out, phosphorylate and anneal oligonucleotides (Top: 5’- CACCGGCGGAATTGACAAGTTCCGA, Bottom: 5’-AAACTCGGAACTTGTCAATTCCGCC), and clone into a pX459 vector.
Transfect 293EL cells with the pX459-gRNA-APP plasmid (Addgene #176487) with Lipofectamine 3000, and select with 1.2 µg/mL of puromycin. Select monoclonal population, and confirm APP deletion by Western blotting.
Stable expression of APPsw,T700N
Stable expression of APPsw,T700N
To create an APP (isoform 751) open reading frame: PCR amplify pENTR-APP751 (open, no stop codon) to replace W752 with a stop codon using forward primer (5'-GCAGAACTAGATCCACCCAGCTTTCTTG) and reverse primer (5'-GGGTGGATCTAGTTCTGCATCTGCTCAAAG).
Use two rounds of PCR to generate pENTR-APPSw,T700N using the following kits and primers: Sw (K651M/N652L): QuickChange II mutagenesis kit; Forward: 5'-tcggaattctgcatccagattcacttcagagatctcctccg; Reverse: 5'-cggaggagatctctgaagtgaatctggatgcagaattccga; T700N: Q5 mutagenesis kit; Forward: 5'- ATCGTCATCAACTTGGTGATG; Reverse: 5'- CACTGTCGCTATGACAAC. Transfer the APPSw,T700N open reading frame in pENTR to Gateway destination vector pHAGE-C-HA-FLAG-puro using Clonase to yield pHAGE-APPSw,T700N-puro.

Note: the stop codon in the APP open reading frame blocks translation into the HA-FLAG tag in this vector.
Prepare a stable cell line by lentiviral transduction of APPSw,T700N to 293EL APP-/- cells followed by monoclonal selection.