Gene description for KRT4
Gene name keratin 4, type II
Gene symbol KRT4
Other names/aliases CK-4
CK4
CYK4
K4
WSN1
Species Homo sapiens
 Database cross references - KRT4
ExoCarta ExoCarta_3851
Vesiclepedia VP_3851
Entrez Gene 3851
HGNC 6441
MIM 123940
 KRT4 identified in exosomes derived from the following tissue/cell type
Chondrocytes 35931686    
Chondrocytes 35931686    
Chondrocytes 35931686    
Chondrocytes 35931686    
Colorectal cancer cells 19837982    
Colorectal cancer cells 34887515    
Mesenchymal stem cells Unpublished / Not applicable
Neuroblastoma cells 25944692    
Retinal pigment epithelial cells 35333565    
Retinal pigment epithelial cells 35333565    
Saliva 19199708    
 Gene ontology annotations for KRT4
Molecular Function
    protein binding GO:0005515 IPI
    structural constituent of skin epidermis GO:0030280 IBA
Biological Process
    cytoskeleton organization GO:0007010 IMP
    cytoskeleton organization GO:0007010 NAS
    epithelial cell differentiation GO:0030855 ISS
    keratinization GO:0031424 IBA
    intermediate filament organization GO:0045109 IBA
    negative regulation of epithelial cell proliferation GO:0050680 ISS
Subcellular Localization
    nucleus GO:0005634 HDA
    cytosol GO:0005829 TAS
    intermediate filament GO:0005882 NAS
    cell surface GO:0009986 IDA
    keratin filament GO:0045095 IBA
    keratin filament GO:0045095 IDA
    intermediate filament cytoskeleton GO:0045111 IDA
 Experiment description of studies that identified KRT4 in exosomes
1
Experiment ID 494
MISEV standards
✔
EM
Biophysical techniques
✔
CD9|CD81|CD151|CD63|CD82|FLOT1|FLOT2|GAPDH|LAMP1|LAMP2|SDCBP|TFRC|TSG101
Enriched markers
✘ Negative markers
✔
NTA
Particle analysis
Identified molecule Protein
Identification method Mass spectrometry
PubMed ID 35931686    
Organism Homo sapiens
Experiment description Extracellular vesicles enriched in connexin 43 promote a senescent phenotype in bone and synovial cells contributing to osteoarthritis progression
Authors "Varela-Eirín M, Carpintero-Fernández P, Guitián-Caamaño A, Varela-Vázquez A, García-Yuste A, Sánchez-Temprano A, Bravo-López SB, Yañez-Cabanas J, Fonseca E, Largo R, Mobasheri A, Caeiro JR, Mayán MD."
Journal name Cell Death Dis
Publication year 2022
Sample Chondrocytes
Sample name Osteoarthritic cartilage
Isolation/purification methods Differential centrifugation
Filtration
Ultracentrifugation
Flotation density -
Molecules identified in the study Protein
Methods used in the study Western blotting
Mass spectometry
2
Experiment ID 496
MISEV standards
✘ Biophysical techniques
✔
CD9|CD151|CD63|CD81|CD82|FLOT1|FLOT2|GAPDH|LAMP1|LAMP2|SDCBP|TFRC|TSG101
Enriched markers
✘ Negative markers
✘ Particle analysis
Identified molecule Protein
Identification method Mass spectrometry
PubMed ID 35931686    
Organism Homo sapiens
Experiment description Extracellular vesicles enriched in connexin 43 promote a senescent phenotype in bone and synovial cells contributing to osteoarthritis progression
Authors "Varela-Eirín M, Carpintero-Fernández P, Guitián-Caamaño A, Varela-Vázquez A, García-Yuste A, Sánchez-Temprano A, Bravo-López SB, Yañez-Cabanas J, Fonseca E, Largo R, Mobasheri A, Caeiro JR, Mayán MD."
Journal name Cell Death Dis
Publication year 2022
Sample Chondrocytes
Sample name Healthy cartilage
Isolation/purification methods Differential centrifugation
Filtration
Ultracentrifugation
Flotation density -
Molecules identified in the study Protein
Methods used in the study Western blotting
Mass spectometry
3
Experiment ID 497
MISEV standards
✘ Biophysical techniques
✔
CD9|CD151|CD63|CD81|CD82|FLOT1|FLOT2|GAPDH|LAMP1|LAMP2|RAB5A|SDCBP|TFRC|TSG101|UCHL1
Enriched markers
✘ Negative markers
✔
NTA
Particle analysis
Identified molecule Protein
Identification method Mass spectrometry
PubMed ID 35931686    
Organism Homo sapiens
Experiment description Extracellular vesicles enriched in connexin 43 promote a senescent phenotype in bone and synovial cells contributing to osteoarthritis progression
Authors "Varela-Eirín M, Carpintero-Fernández P, Guitián-Caamaño A, Varela-Vázquez A, García-Yuste A, Sánchez-Temprano A, Bravo-López SB, Yañez-Cabanas J, Fonseca E, Largo R, Mobasheri A, Caeiro JR, Mayán MD."
Journal name Cell Death Dis
Publication year 2022
Sample Chondrocytes
Sample name T/C-28a2
Isolation/purification methods Differential centrifugation
Filtration
Ultracentrifugation
Flotation density -
Molecules identified in the study Protein
Methods used in the study Western blotting
Mass spectometry
4
Experiment ID 498
MISEV standards
✔
EM
Biophysical techniques
✔
CD9|CD151|CD63|CD81|CD82|FLOT1|FLOT2|GAPDH|LAMP1|LAMP2|RAB5A|SDCBP|TFRC|TSG101|UCHL1
Enriched markers
✘ Negative markers
✔
NTA
Particle analysis
Identified molecule Protein
Identification method Mass spectrometry
PubMed ID 35931686    
Organism Homo sapiens
Experiment description Extracellular vesicles enriched in connexin 43 promote a senescent phenotype in bone and synovial cells contributing to osteoarthritis progression
Authors "Varela-Eirín M, Carpintero-Fernández P, Guitián-Caamaño A, Varela-Vázquez A, García-Yuste A, Sánchez-Temprano A, Bravo-López SB, Yañez-Cabanas J, Fonseca E, Largo R, Mobasheri A, Caeiro JR, Mayán MD."
Journal name Cell Death Dis
Publication year 2022
Sample Chondrocytes
Sample name T/C-28a2
Isolation/purification methods Differential centrifugation
Filtration
Ultracentrifugation
Flotation density -
Molecules identified in the study Protein
Methods used in the study Western blotting
Mass spectometry
5
Experiment ID 21
MISEV standards
✔
EM|IEM
Biophysical techniques
✔
Alix|TSG101|HSP70|CD63
Enriched markers
✘ Negative markers
✘ Particle analysis
Identified molecule protein
Identification method
Mass spectrometry   
PubMed ID 19837982    
Organism Homo sapiens
Experiment description Proteomic and bioinformatic analysis of immunoaffinity-purified exosomes derived from the human colon tumor cell line LIM1215.
Authors "Suresh Mathivanan, Justin W.E. Lim, Bow J. Tauro, Hong Ji, Robert L. Moritz and Richard J. Simpson"
Journal name MCP
Publication year 2009
Sample Colorectal cancer cells
Sample name LIM1215
Isolation/purification methods Filtration
Ultracentrifugation
Sucrose density gradient
Flotation density 1.10-1.12 g/mL
Molecules identified in the study Protein
Methods used in the study Mass spectrometry [Orbitrap]
Western blotting
6
Experiment ID 1203
MISEV standards
✔
EM
Biophysical techniques
✔
SDCBP|FLOT1|CD9|CD81|CD63|EPCAM|GAPDH|LAMP1|TFRC|CD151|CD82|LAMP2|RAB35|TSG101|FLOT2|RAB5B|ICAM1|RAB5A
Enriched markers
✘ Negative markers
✘ Particle analysis
Identified molecule protein
Identification method Mass spectrometry
PubMed ID 34887515    
Organism Homo sapiens
Experiment description Supermeres are functional extracellular nanoparticles replete with disease biomarkers and therapeutic targets
Authors "Zhang Q, Jeppesen DK, Higginbotham JN, Graves-Deal R, Trinh VQ, Ramirez MA, Sohn Y, Neininger AC, Taneja N, McKinley ET, Niitsu H, Cao Z, Evans R, Glass SE, Ray KC, Fissell WH, Hill S, Rose KL, Huh WJ, Washington MK, Ayers GD, Burnette DT, Sharma S, Rome LH, Franklin JL, Lee YA, Liu Q, Coffey RJ."
Journal name Nat Cell Biol
Publication year 2021
Sample Colorectal cancer cells
Sample name DiFi
Isolation/purification methods Differential centrifugation
Filtration
Centrifugal ultrafiltration
Ultracentrifugation
OptiPrep density gradient centrifugation
Flotation density -
Molecules identified in the study Protein
miRNA
Methods used in the study Western blotting
Mass spectrometry
RNA sequencing
7
Experiment ID 126
MISEV standards
✘ Biophysical techniques
✔
GAPDH
Enriched markers
✘ Negative markers
✘ Particle analysis
Identified molecule protein
Identification method Mass spectrometry [LTQ-FT Ultra]
PubMed ID Unpublished / Not applicable
Organism Homo sapiens
Experiment description Mesenchymal Stem Cell Exosomes: The Future MSC-based Therapy?
Authors "Ruenn Chai Lai, Ronne Wee Yeh Yeo, Soon Sim Tan, Bin Zhang, Yijun Yin, Newman Siu Kwan Sze, Andre Choo, and Sai Kiang Lim"
Journal name Mesenchymal Stem Cell Therapy
Publication year 2011
Sample Mesenchymal stem cells
Sample name huES9.E1
Isolation/purification methods HPLC
Flotation density -
Molecules identified in the study Protein
Methods used in the study Western blotting
Antobody array
Mass spectrometry
8
Experiment ID 224
MISEV standards
✔
EM|AFM
Biophysical techniques
✔
Alix|TSG101|CD63|CD81
Enriched markers
✔
GOLGA2
Negative markers
✘ Particle analysis
Identified molecule protein
Identification method Mass spectrometry
PubMed ID 25944692    
Organism Homo sapiens
Experiment description Proteogenomic analysis reveals exosomes are more oncogenic than ectosomes
Authors "Keerthikumar S, Gangoda L, Liem M, Fonseka P, Atukorala I, Ozcitti C, Mechler A, Adda CG, Ang CS, Mathivanan S"
Journal name Oncotarget
Publication year 2015
Sample Neuroblastoma cells
Sample name SH-SY5Y
Isolation/purification methods Differential centrifugation
Ultracentrifugation
OptiPrep density gradient
Flotation density 1.10 g/mL
Molecules identified in the study Protein
Methods used in the study Mass spectrometry
Western blotting
9
Experiment ID 834
MISEV standards
✔
EM
Biophysical techniques
✔
LAMP2|CD63|FLOT1|ITGA2B|ICAM1|CD9|CD151|TFRC|RAB5A|GAPDH|AQP1|TSG101
Enriched markers
✔
CANX
Negative markers
✔
NTA
Particle analysis
Identified molecule Protein
Identification method Mass spectrometry
PubMed ID 35333565    
Organism Homo sapiens
Experiment description LAMP2A regulates the loading of proteins into exosomes
Authors "Ferreira JV, da Rosa Soares A, Ramalho J, Máximo Carvalho C, Cardoso MH, Pintado P, Carvalho AS, Beck HC, Matthiesen R, Zuzarte M, Girão H, van Niel G, Pereira P"
Journal name Sci Adv
Publication year 2022
Sample Retinal pigment epithelial cells
Sample name ARPE-19
Isolation/purification methods Differential centrifugation
Filtration
Ultracentrifugation
Flotation density -
Molecules identified in the study Protein
Methods used in the study Western blotting
Mass spectrometry
10
Experiment ID 835
MISEV standards
✔
EM
Biophysical techniques
✔
CD63|FLOT1|ITGA2B|ICAM1|CD9|CD151|TFRC|RAB5A|GAPDH|AQP1|TSG101
Enriched markers
✔
CANX
Negative markers
✔
NTA
Particle analysis
Identified molecule Protein
Identification method Mass spectrometry
PubMed ID 35333565    
Organism Homo sapiens
Experiment description LAMP2A regulates the loading of proteins into exosomes
Authors "Ferreira JV, da Rosa Soares A, Ramalho J, Máximo Carvalho C, Cardoso MH, Pintado P, Carvalho AS, Beck HC, Matthiesen R, Zuzarte M, Girão H, van Niel G, Pereira P"
Journal name Sci Adv
Publication year 2022
Sample Retinal pigment epithelial cells
Sample name ARPE-19
Isolation/purification methods Differential centrifugation
Filtration
Ultracentrifugation
Flotation density -
Molecules identified in the study Protein
Methods used in the study Western blotting
Mass spectrometry
11
Experiment ID 66
MISEV standards
✔
IEM
Biophysical techniques
✔
TSG101|Alix|CD63|CD81
Enriched markers
✘ Negative markers
✘ Particle analysis
Identified molecule protein
Identification method Mass spectrometry
PubMed ID 19199708    
Organism Homo sapiens
Experiment description Proteomic analysis of human parotid gland exosomes by multidimensional protein identification technology (MudPIT).
Authors "Gonzalez-Begne M, Lu B, Han X, Hagen FK, Hand AR, Melvin JE, Yates JR"
Journal name JPR
Publication year 2009
Sample Saliva
Sample name Saliva
Isolation/purification methods Differential centrifugation
Flotation density -
Molecules identified in the study Protein
Methods used in the study Mass spectrometry [LTQ]
Western blotting
Immunoelectron Microscopy
 Protein-protein interactions for KRT4
  Protein Interactor ExoCarta ID Identification method PubMed Species
1 CEP57  
Two-hybrid Homo sapiens
2 EPPK1 83481
Affinity Capture-MS Homo sapiens
3 KRT36 8689
Two-hybrid Homo sapiens
4 KRT37 8688
Two-hybrid Homo sapiens
5 KRT27 342574
Two-hybrid Homo sapiens
6 GRB2 2885
Affinity Capture-MS Homo sapiens
7 USP25  
Affinity Capture-MS Homo sapiens
8 METTL14  
Affinity Capture-MS Homo sapiens
9 KRT25 147183
Two-hybrid Homo sapiens
10 KRT33B 3884
Two-hybrid Homo sapiens
Two-hybrid Homo sapiens
11 USPL1  
Affinity Capture-MS Homo sapiens
12 ATG9A 79065
Proximity Label-MS Homo sapiens
13 USP1 7398
Affinity Capture-MS Homo sapiens
14 WWOX 51741
Affinity Capture-MS Homo sapiens
15 C14orf119  
Two-hybrid Homo sapiens
16 DDX3X 1654
Affinity Capture-MS Homo sapiens
17 CRK 1398
Affinity Capture-MS Homo sapiens
18 THOC2 57187
Affinity Capture-MS Homo sapiens
19 UCHL1 7345
Affinity Capture-MS Homo sapiens
20 CCDC57 284001
Two-hybrid Homo sapiens
21 EPS15 2060
Affinity Capture-MS Homo sapiens
22 CUL3 8452
Affinity Capture-MS Homo sapiens
23 NUMA1 4926
Affinity Capture-MS Homo sapiens
24 KRT28 162605
Two-hybrid Homo sapiens
25 RNF208  
Affinity Capture-MS Homo sapiens
26 TUBGCP4 27229
Two-hybrid Homo sapiens
27 TRIM54  
Two-hybrid Homo sapiens
28 KRT35 3886
Two-hybrid Homo sapiens
29 KRT15 3866
Two-hybrid Homo sapiens
Two-hybrid Homo sapiens
30 KRT24 192666
Two-hybrid Homo sapiens
31 UBASH3B 84959
Affinity Capture-MS Homo sapiens
32 B3GNT2 10678
Affinity Capture-MS Homo sapiens
33 KRT38 8687
Two-hybrid Homo sapiens
Two-hybrid Homo sapiens
Two-hybrid Homo sapiens
34 BAG1 573
Affinity Capture-MS Homo sapiens
35 ATG4B 23192
Affinity Capture-MS Homo sapiens
36 KRT13 3860
Two-hybrid Homo sapiens
Two-hybrid Homo sapiens
37 KRT40  
Two-hybrid Homo sapiens
Two-hybrid Homo sapiens
38 PIK3R2 5296
Affinity Capture-MS Homo sapiens
39 MYC  
Affinity Capture-MS Homo sapiens
40 KRT19 3880
Two-hybrid Homo sapiens
41 DDX39B 7919
Affinity Capture-MS Homo sapiens
42 KRT16 3868
Two-hybrid Homo sapiens
43 CYLD  
Affinity Capture-MS Homo sapiens
44 SHC1 6464
Affinity Capture-MS Homo sapiens
View the network image/svg+xml
 Pathways in which KRT4 is involved
PathwayEvidenceSource
Developmental Biology TAS Reactome
Formation of the cornified envelope TAS Reactome
Keratinization TAS Reactome





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