CD9 antigen - P21926 (CD9_HUMAN)

 

Protein Feature View of PDB entries mapped to a UniProtKB sequence  

 
Function
Integral membrane protein associated with integrins, which regulates different processes, such as sperm-egg fusion, platelet activation and aggregation, and cell adhesion (PubMed:8478605, PubMed:14575715, PubMed:18541721). Present at the cell surface of oocytes and plays a key role in sperm-egg fusion, possibly by organizing multiprotein complexes and the morphology of the membrane required for the fusion (By similarity). Acts as a receptor for PSG17 (By similarity). Involved in platelet activation and aggregation (PubMed:18541721). Regulates paranodal junction formation (By similarity). Involved in cell adhesion, cell motility and tumor metastasis (PubMed:8478605, PubMed:7511626). UniProt
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Subunit Structure
Forms both disulfide-linked homodimers and higher homooligomers as well as heterooligomers with other members of the tetraspanin family (PubMed:14556650). Interacts (via the second extracellular domain) with integrin ITGAV:ITGB3 (PubMed:19640571, PubMed:27993971). Interacts with integrin ITGA6:ITGB1; interaction takes place in oocytes and is involved in sperm-egg fusion (By similarity). Interacts with CD63; identified in a complex with CD63 and ITGB3 (PubMed:19640571). Associates with CR2/CD21 and with PTGFRN/CD9P1 (PubMed:11278880). Interacts directly with IGSF8 (PubMed:11504738). Interacts with PDPN; this interaction is homophilic and attenuates platelet aggregation and pulmonary metastasis induced by PDPN (PubMed:18541721). UniProt
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Variation data (sourced from UniProt) shows non-genetic variation from the ExPASy   and dbSNP   websites.
Data in yellow originates from Pfam  , by interacting with the HMMER3 web site  
Data in purple originates from Phosphosite  .
Data in orange originates from the SCOP   (version 1.75) and SCOPe   (version 2.04) classifications.
Data in grey has been calculated using BioJava  . Protein disorder predictions are based on JRONN (Troshin, P. and Barton, G. J. unpublished), a Java implementation of RONN  
  • Red: potentially disorderd region
  • Blue: probably ordered region.
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  • Blue: hydrophilic.
Data in lilac represent the genomic exon structure projected onto the UniProt sequence.
Data in blue originates from PDB
  • Secstruc: Secondary structure projected from representative PDB entries onto the UniProt sequence.
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Data in red indicates combined ranges of Homology Models from the SWISS-MODEL Repository  
The PDB to UniProt mapping is based on the data provided by the EBI SIFTS project. See also Velankar et al., Nucleic Acids Research 33, D262-265 (2005).
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