PDZ

The PDZ domain is a common structural domain of 80-90 amino-acids found in the signaling proteins of bacteria, yeast, plants, viruses and animals. PDZ is an acronym combining the first letters of three proteins — post synaptic density protein (PSD95), Drosophila disc large tumor suppressor (Dlg1), and zonula occludens-1 protein (zo-1) — which were first discovered to share the domain. PDZ domains have previously been referred to as DHR (Dlg homologous region) or GLGF (glycine-leucine-glycine-phenylalanine) domains. These domains help anchor transmembrane proteins to the cytoskeleton and hold together signaling complexes.

In general PDZ domains bind to a short region of the C-terminus of other specific proteins. These short regions bind to the PDZ domain by beta sheet augmentation. This means that the beta sheet in the PDZ domain is extended by the addition of a further beta strand from the tail of the binding partner protein.

Proteins containing this domain

Examples of PDZ domain-containing proteins (Figure from Lee et al. 2010). Proteins are indicated by black lines scaled to the length of the primary sequence of the protein.

PDZ domains are found in many thousands of known proteins. PDZ domain proteins are widespread in eukaryotes and eubacteria, whereas there are very few examples of the protein in archaebacteria. PDZ domains are often associated with other protein domains and these combinations allow them to carry out their specific functions. For example the PDZ domains in the PSD-95 protein are found associated with an SH3 domain and a guanylate kinase domain.

Human

There are roughly 260 human PDZ domains, though since several PDZ domain-containing proteins hold several domains, the actual number of PDZ proteins is closer to 180. Listed below are some of the better studied members of this family:

• Cystic fibrosis transmembrane conductance regulator (CFTR)
• Erbin
• Htra1
• Htra2
• Htra3
• PSD-95
• SAP97
• CARD11
• PTP-BL

Below is a complete list:

AAG12; AHNAK; AHNAK2; AIP1; ALP; APBA1; APBA2; APBA3; ARHGAP21; ARHGAP23; ARHGEF11; ARHGEF12; CASK; CLP-36; CNKSR2; CNKSR3; DFNB31; DLG1; DLG2; DLG3; DLG4; DLG5; DVL1; DVL1L1; DVL2; DVL3; ERBB2IP; FRMPD1; FRMPD2; FRMPD2L1; FRMPD3; FRMPD4; GIPC1; GIPC2; GIPC3; GOPC; GRASP; GRIP1; GRIP2; HTRA1; HTRA2; HTRA3; HTRA4; IL16; INADL; KIAA1849; LDB3; LIMK1; LIMK2; LIN7A; LIN7B; LIN7C; LMO7; LNX1; LNX2; LRRC7; MAGI1; MAGI2; MAGI3; MAGIX; MAST1; MAST2; MAST3; MAST4; MCSP; MLLT4; MPDZ; MPP1; MPP2; MPP3; MPP4; MPP5; MPP6; MPP7; MYO18A;  ;NOS1; PARD3; PARD3B; PARD6A; PARD6B; PARD6G; PDLIM1; PDLIM2; PDLIM3; PDLIM4; PDLIM5; PDLIM7; PDZD11; PDZD2; PDZD3; PDZD4; PDZD5A; PDZD7; PDZD8; PDZK1; PDZRN3; PDZRN4; PICK1; PPP1R9A; PPP1R9B; PREX1; PRX; PSCDBP; PTPN13; PTPN3; PTPN4; RAPGEF2; RAPGEF6; RGS12; RGS3; RHPN1; RIL; RIMS1; RIMS2; SCN5A; SCRIB; SDCBP; SDCBP2; SHANK1; SHANK2; SHANK3; SHROOM2; SHROOM3; SHROOM4; SIPA1; SIPA1L1; SIPA1L2; SIPA1L3; SLC9A3R1; SLC9A3R2; SNTA1; SNTB1; SNTB2; SNTG1; SNTG2; SNX27; SPAL2; STXBP4; SYNJ2BP; SYNPO2; SYNPO2L; TAX1BP3; TIAM1; TIAM2; TJP1; TJP2; TJP3; TRPC4; TRPC5; USH1C; WHRN;

Virus

Tax1