claudin-1; senescence-associated epithelial membrane protein (CLDN1, CLD1, SEMP1, UNQ481/PRO944)

Function

• plays a major role in tight junction-specific obliteration of the intercellular space, through Ca+2-independent cell-adhesion activity (putative)
• acts as a co-receptor for HCV entry into hepatic cells
• can form homo- & heteropolymers with other CLDN homopolymers
• interacts with CLDN3, but not CLDN2 homopolymers
• directly interacts with TJP1/ZO-1, TJP2/ZO-2 & TJP3/ZO-3
• interacts with MPDZ & INADL (putative)
• may interact with HCV E1 & E2 proteins

Structure

• belongs to the claudin family

Compartment

• cell junction, tight junction
• cell membrane; multi-pass membrane protein

Expression

• strongly expressed in liver & kidney
• expressed in heart, brain, spleen, lung & testis

Pathology

• defects in CLDN1 are the cause of ichthyosis-sclerosing cholangitis neonatal syndrome

More general terms

• claudin
• phosphoprotein

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=9076
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:9076
• OMIM: https://mirror.omim.org/entry/603718
• OMIM: https://mirror.omim.org/entry/607626
• UniProt: http://www.uniprot.org/uniprot/O95832.html