Outer membrane protein (OmpH-like); This family includes outer membrane proteins such as OmpH among others. Skp (OmpH) has been characterized as a molecular chaperone that interacts with unfolded proteins as they emerge in the periplasm from the Sec translocation machinery.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 115534505  421 EKCFRTSERCNKANAELKTSL----NKIKILEKKLSAEKRAFKENQETWEKKLEELQTELQAKERTIQEFQDK 489
Cdd:pfam03938   8 QKILEESPEGKAAQAQLEKKFkkrqAELEAKQKELQKLYEELQKDGALLEEEREEKEQELQKKEQELQQLQQK 80

RING finger, H2 subclass, found in RING finger proteins RNF126, RNF115, and similar proteins; This subfamily includes RING finger proteins RNF126, RNF115, and similar proteins. RNF126 is a Bag6-dependent E3 ubiquitin ligase that is involved in the mislocalized protein (MLP) pathway of quality control. It regulates the retrograde sorting of the cation-independent mannose 6-phosphate receptor (CI-MPR). RNF126 promotes cancer cell proliferation by targeting the tumor suppressor p21 for ubiquitin-mediated degradation, and could be a novel therapeutic target in breast and prostate cancers. It is also able to ubiquitylate cytidine deaminase (AID), a poorly soluble protein that is essential for antibody diversification. RNF115, also known as Rab7-interacting ring finger protein (Rabring 7), or zinc finger protein 364 (ZNF364), or breast cancer-associated gene 2 (BCA2), is an E3 ubiquitin-protein ligase that is an endogenous inhibitor of adenosine monophosphate-activated protein kinase (AMPK) activation; this inhibition increases the efficacy of metformin in breast cancer cells. It also functions as a cofactor in the restriction imposed by tetherin on HIV-1, and targets HIV-1 Gag for lysosomal degradation, impairing virus assembly and release, in a tetherin-independent manner. Moreover, RNF115 is a Rab7-binding protein that stimulates c-Myc degradation through mono-ubiquitination of MM-1. It also plays crucial roles as a Rab7 target protein in vesicle traffic to late endosome/lysosome and lysosome biogenesis. RNF115 and RNF126 associate with the epidermal growth factor receptor (EGFR) and promote ubiquitylation of EGFR, suggesting they play a role in the ubiquitin-dependent sorting and downregulation of membrane receptors. Both of them contain an N-terminal BCA2 Zinc-finger domain (BZF), AKT-phosphorylation sites, and a C-terminal C3H2C3-type RING-H2 finger.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|...
gi 115534505 527 ECIICREDIDLENGTVQCPrCTEIYHSHCATQWLSQKPTCPKC 569
Cdd:cd16667    1 ECAVCKEDFEVGEEVRQLP-CKHLFHPDCIVPWLELHNSCPVC 42

Outer membrane protein (OmpH-like); This family includes outer membrane proteins such as OmpH among others. Skp (OmpH) has been characterized as a molecular chaperone that interacts with unfolded proteins as they emerge in the periplasm from the Sec translocation machinery.

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 115534505   421 EKCFRTSERCNKANAELKTSLNK----IKILEKKLSAEKRAFKENQETW-EKKLEELQTELQAKERTIQEFQDK 489
Cdd:smart00935   7 QKILQESPAGKAAQKQLEKEFKKrqaeLEKLEKELQKLKEKLQKDAATLsEAAREKKEKELQKKVQEFQRKQQK 80

HRD ubiquitin ligase complex, ER membrane component [Posttranslational modification, protein turnover, chaperones];

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 115534505 502 FLRDGEELIATFDVTSSNATEEFESECIICREDIdLENGTVQCPR----------CTEIYHSHCATQWLSQKPTCPKC 569
Cdd:COG5243  264 FRRATKDLNAMYPTATEEQLTNSDRTCTICMDEM-FHPDHEPLPRgldmtpkrlpCGHILHLHCLKNWLERQQTCPIC 340

RING-H2 zinc finger domain; There are 8 cysteine/ histidine residues which are proposed to be the conserved residues involved in zinc binding. The protein, of which this domain is the conserved region, participates in diverse functions relevant to chromosome metabolism and cell cycle control.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 115534505  528 CIICREDID------LENGTVQCP----RCTEIYHSHCATQWLSQKPTCPKC 569
Cdd:pfam12678   3 CAICRNPFMepcpecQAPGDDECPvvwgECGHAFHLHCISRWLKTNNTCPLC 54

RING finger, H2 subclass, found in the PA-TM-RING ubiquitin ligase family; The PA-TM-RING family represents a group of transmembrane-type E3 ubiquitin ligases, which has been characterized by an N-terminal transient signal peptide, a PA (protease-associated) domain, a TM (transmembrane) domain, as well as a C-terminal C3H2C3-type RING-H2 finger domain. It includes RNF13, RNF167, ZNRF4 (zinc and RING finger 4), GRAIL (gene related to anergy in lymphocytes)/RNF128, RNF130, RNF133, RNF148, RNF149 and RNF150 (which are more closely related), as well as RNF43 and ZNRF3, which have substantially longer C-terminal tail extensions compared with the others. PA-TM-RING proteins are expressed at low levels in all mammalian tissues and species, but they are not present in yeast. They play a common regulatory role in intracellular trafficking/sorting, suggesting that abrogation of their function may result in dysregulation of cellular signaling events in cancer.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|...
gi 115534505 527 ECIICREDIDLENGTVQCPrCTEIYHSHCATQWLSQKPTCPKC 569
Cdd:cd16454    1 TCAICLEEFKEGEKVRVLP-CNHLFHKDCIDPWLEQHNTCPLC 42

RING finger, H2 subclass, found in synoviolin and similar proteins; Synoviolin, also known as synovial apoptosis inhibitor 1 (Syvn1), Hrd1, or Der3, is an endoplasmic reticulum (ER)-anchoring E3 ubiquitin ligase that functions as a suppressor of ER stress-induced apoptosis and plays a role in homeostasis maintenance. It also targets tumor suppressor gene p53 for proteasomal degradation, suggesting crosstalk between ER associated degradation (ERAD) and p53 mediated apoptotic pathway under ER stress. Moreover, synoviolin controls body weight and mitochondrial biogenesis through negative regulation of the thermogenic coactivator peroxisome proliferator-activated receptor coactivator (PGC)-1beta. It upregulates amyloid beta production by targeting a negative regulator of gamma-secretase, Retention in endoplasmic reticulum 1 (Rer1), for degradation. It is also involved in the degradation of endogenous immature nicastrin, and affects amyloid beta-protein generation. Moreover, synoviolin is highly expressed in rheumatoid synovial cells and may be involved in the pathogenesis of rheumatoid arthritis (RA). It functions as an anti-apoptotic factor that is responsible for the outgrowth of synovial cells during the development of RA. It promotes inositol-requiring enzyme 1 (IRE1) ubiquitination and degradation in synovial fibroblasts with collagen-induced arthritis. Furthermore, the upregulation of synoviolin may represent a protective response against neurodegeneration in Parkinson's disease (PD). In addition, synoviolin is involved in liver fibrogenesis. Synoviolin contains a C3H2C2-type RING-H2 finger.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....
gi 115534505 528 CIICREDIdlengTVQCPR--CTEIYHSHCATQWLSQKPTCPKC 569
Cdd:cd16479    4 CIICREEM-----TVGAKKlpCGHIFHLSCLRSWLQRQQTCPTC 42

RING finger, H2 subclass, found in RING finger protein 126 (RNF126) and similar proteins; RNF126 is a Bag6-dependent E3 ubiquitin ligase that is involved in the mislocalized protein (MLP) pathway of quality control. It regulates the retrograde sorting of the cation-independent mannose 6-phosphate receptor (CI-MPR). Moreover, RNF126 promotes cancer cell proliferation by targeting the tumor suppressor p21 for ubiquitin-mediated degradation, and could be a novel therapeutic target in breast and prostate cancers. It is also able to ubiquitylate cytidine deaminase (AID), a poorly soluble protein that is essential for antibody diversification. In addition, RNF126 and the related protein, RNF115 associate with the epidermal growth factor receptor (EGFR) and promote ubiquitylation of EGFR, suggesting they play a role in the ubiquitin-dependent sorting and downregulation of membrane receptors. RNF126 contains an N-terminal BCA2 Zinc-finger domain (BZF), the AKT-phosphorylation sites, and the C-terminal C3H2C3-type RING-H2 finger.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|...
gi 115534505 527 ECIICREDIDLENGTVQCPrCTEIYHSHCATQWLSQKPTCPKC 569
Cdd:cd16801    1 ECPVCKEDYTVGENVRQLP-CNHLFHNDCIVPWLEQHDTCPVC 42

RING finger, H2 subclass, found in RING finger protein 115 (RNF115) and similar proteins; RNF115, also known as Rab7-interacting ring finger protein (Rabring 7), or zinc finger protein 364 (ZNF364), or breast cancer-associated gene 2 (BCA2), is an E3 ubiquitin-protein ligase that is an endogenous inhibitor of adenosine monophosphate-activated protein kinase (AMPK) activation and its inhibition increases the efficacy of metformin in breast cancer cells. It also functions as a co-factor in the restriction imposed by tetherin on HIV-1, and targets HIV-1 Gag for lysosomal degradation, impairing virus assembly and release, in a tetherin-independent manner. Moreover, RNF115 is a Rab7-binding protein that stimulates c-Myc degradation through mono-ubiquitination of MM-1. It also plays crucial roles as a Rab7 target protein in vesicle traffic to late endosome/lysosome and lysosome biogenesis. Furthermore, RNF115 and the related protein, RNF126 associate with the epidermal growth factor receptor (EGFR) and promote ubiquitylation of EGFR, suggesting they play a role in the ubiquitin-dependent sorting and downregulation of membrane receptors. RNF115 contains an N-terminal BCA2 Zinc-finger domain (BZF), the AKT-phosphorylation sites, and the C-terminal C3H2C3-type RING-H2 finger.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|...
gi 115534505 527 ECIICREDIDLENGTVQCPrCTEIYHSHCATQWLSQKPTCPKC 569
Cdd:cd16800    2 ECPVCKEDYTVGEQVRQLP-CNHFFHSDCIVPWLELHDTCPVC 43

RING finger, H2 subclass, found in RING finger proteins RNF24, RNF122, and similar proteins; This subfamily includes RNF24, RNF122, and similar proteins. RNF24 is an intrinsic membrane protein localized in the Golgi apparatus. It specifically interacts with the ankyrin-repeats domains (ARDs) of TRPC1, -3, -4, -5, -6, and -7, and affects TRPC intracellular trafficking without affecting their activity. RNF122 is a RING finger protein associated with HEK 293T cell viability. It is localized to the endoplasmic reticulum (ER) and the Golgi apparatus, and overexpressed in anaplastic thyroid cancer cells. RNF122 functions as an E3 ubiquitin ligase that can ubiquitinate itself and undergo degradation through its RING finger in a proteasome-dependent manner. Both RNF24 and RNF122 contain an N-terminal transmembrane domain and a C-terminal C3H2C3-type RING-H2 finger.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|..
gi 115534505 528 CIICREDIDLENGTVQCPrCTEIYHSHCATQWLSQKPTCPKC 569
Cdd:cd16469    3 CAVCLEEFKLKEELGVCP-CGHAFHTKCLKKWLEVRNSCPIC 43

RING finger, H2 subclass, found in Arabidopsis thaliana RING-type E3 ubiquitin transferase BIG BROTHER (BB) and similar proteins; BB (also known as protein ENHANCER OF DA1-1 or EOD1) is an E3 ubiquitin-protein ligase that limits organ size, and possibly seed size, in a dose-dependent manner. It negatively regulates the duration of cell proliferation in leaves and petals independently of the major phytohormones (e.g. auxin, cytokinin, gibberellin, brassinosteroids, ethylene, abscisic acid, jasmonic acid), probably by targeting growth stimulators for degradation. It limits the proliferation of root meristematic cells. BB polyubiquitinates DA1. It is involved in the promotion of leaf senescence, in addition to its function in restricting plant growth. BB-related is an E3 ubiquitin-ligase probably involved in organ size regulation. Members of this subfamily contain a C3H2C3-type RING-H2 finger.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*
gi 115534505 525 ESECIICREDIDLENGTVQCPrCTEIYHSHCATQWLSQKPTCPKC 569
Cdd:cd23115    4 NERCVICRLEYEEGEDLLTLP-CKHCYHSECIQQWLQINKVCPVC 47

H2 subclass of RING (RING-H2) fingers and its variants; The RING finger is a specialized type of Zn-finger of 40 to 60 residues that binds two atoms of zinc. It is defined by the "cross-brace" motif that chelates zinc atoms by eight amino acid residues, typically Cys or His, arranged in a characteristic spacing. Canonical RING motifs have been categorized into two major subclasses, RING-HC (C3HC4-type) and RING-H2 (C3H2C3-type), according to their Cys/His content. There are also many variants of RING fingers: some have different Cys/His patterns while some lack a single Cys or His residue at typical Zn ligand positions (the fourth or eighth zinc ligand is prevalently exchanged for an Asp, which can indeed chelate Zn in a RING finger as well). This family corresponds to the H2 subclass of RING (RING-H2) finger proteins that are characterized by containing C3H2C3-type canonical RING-H2 fingers or noncanonical RING-H2 finger variants, including C4HC3- (RING-CH alias RINGv), C3H3C2-, C3H2C2D-, C3DHC3-, and C4HC2H-type modified RING-H2 fingers. The canonical RING-H2 finger has been defined as C-X2-C-X(9-39)-C-X(1-3)-H-X(2-3)-H-X2-C-X(4-48)-C-X2-C, X is any amino acid and the number of X residues varies in different fingers. It binds two Zn ions in a unique "cross-brace" arrangement, which distinguishes it from tandem zinc fingers and other similar motifs. RING-H2 finger can be found in a group of diverse proteins with a variety of cellular functions, including oncogenesis, development, viral replication, signal transduction, the cell cycle and apoptosis. Many of them are ubiquitin-protein ligases (E3s) that serves as a scaffold for binding to ubiquitin-conjugating enzymes (E2s, also referred to as ubiquitin carrier proteins or UBCs) in close proximity to substrate proteins, which enables efficient transfer of ubiquitin from E2 to the substrates.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|...
gi 115534505 528 CIICREDIDLENGTVQCPrCTEIYHSHCATQWL-SQKPTCPKC 569
Cdd:cd16448    1 CVICLEEFEEGDVVRLLP-CGHVFHLACILRWLeSGNNTCPLC 42

Periplasmic chaperone for outer membrane proteins, Skp family [Cell wall/membrane/envelope biogenesis, Posttranslational modification, protein turnover, chaperones];

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*..
gi 115534505 434 NAELKTSLNKIKILEKKLSAEKRAFKENQETW-EKKLEELQTELQAKERTIQEFQDK 489
Cdd:COG2825   49 EKEFKKRQAELQKLEKELQALQEKLQKEAATLsEEERQKKERELQKKQQELQRKQQE 105

RING finger, H2 subclass, found in Saccharomyces cerevisiae transmembrane E3 ubiquitin-protein ligase 1 (TUL1) and similar proteins; This subfamily includes Saccharomyces cerevisiae TUL1, Schizosaccharomyces pombe DSC E3 ubiquitin ligase complex subunit 1 (DSC1), and Arabidopsis thaliana protein FLYING SAUCER 2 (FLY2). TUL1 is the catalytic component of DSC E3 ubiquitin ligase complexes that tag proteins present in Golgi, endosome and vacuole membranes and function in protein homeostasis under non-stress conditions, and support a role in protein quality control. It mediates ubiquitination of vacuolar proteins such as CPS1, PPN1, PEP12 and other proteins containing exposed hydrophilic residues within their transmembrane domains, leading to their sorting into internal vesicles in late endosomes. TUL1 also targets the unpalmitoylated endosomal SNARE TLG1 to the multivesicular body (MVB) pathway. DSC1, also known as defective for SREBP cleavage protein 1, is the catalytic component of the DSC E3 ubiquitin ligase complex required for the sre1 transcriptional activator proteolytic cleavage to release the soluble transcription factor from the membrane in low oxygen or sterol conditions. FLY2 acts as an E3 ubiquitin-protein ligase that may be involved in xylem development. Members of this subfamily contain a C3H2C3-type RING-H2 finger.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|...
gi 115534505 522 EEFESECIICREDIDL-ENGTVQCPR----CTEIYHSHCATQWLSQKPTCPKC 569
Cdd:cd23117    1 ENGSVDCVICMSDIELpSTNSVRRDYmvtpCNHIFHTNCLERWMDIKLECPTC 53

RING finger, H2 subclass, found in TRAF-interacting protein (TRAIP) and similar proteins; TRAIP, also known as RING finger protein 206 (RNF206) or TRIP, is a ubiquitously expressed nucleolar E3 ubiquitin ligase important for cellular proliferation and differentiation. It is found near mitotic chromosomes and functions as a regulator of the spindle assembly checkpoint. TRAIP interacts with tumor necrosis factor (TNF)-receptor-associated factor (TRAF) proteins and inhibits TNF-alpha-mediated nuclear factor (NF)-kappaB activation. It also interacts with two tumor suppressors CYLD and spleen tyrosine kinase (Syk), and DNA polymerase eta, which facilitates translesional synthesis after DNA damage. TRAIP contains an N-terminal C3H2C2-type RING-H2 finger and an extended coiled-coil domain.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|..
gi 115534505 528 CIICREDIDLENgTVQCPRCTEIYHSHCATQWLSQKPTCPKC 569
Cdd:cd16480    2 CTICSDFFDNSR-DVAAIHCGHTFHYDCLLQWFDTSRTCPQC 42

PHD finger superfamily; The PHD finger superfamily includes a canonical plant homeodomain (PHD) finger typically characterized as Cys4HisCys3, and a non-canonical extended PHD finger, characterized as Cys2HisCys5HisCys2His. Variations include the RAG2 PHD finger characterized by Cys3His2Cys2His and the PHD finger 5 found in nuclear receptor-binding SET domain-containing proteins characterized by Cys4HisCys2His. The PHD finger is also termed LAP (leukemia-associated protein) motif or TTC (trithorax consensus) domain. Single or multiple copies of PHD fingers have been found in a variety of eukaryotic proteins involved in the control of gene transcription and chromatin dynamics. PHD fingers can recognize the unmodified and modified histone H3 tail, and some have been found to interact with non-histone proteins. They also function as epigenome readers controlling gene expression through molecular recruitment of multi-protein complexes of chromatin regulators and transcription factors. The PHD finger domain SF is structurally similar to the RING and FYVE_like superfamilies.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*..
gi 115534505 528 CIICREDIDLENGTVQCPRCTEIYHSHCA-----TQWLSQKPTCPKC 569
Cdd:cd15489    2 CIVCGKGGDLGGELLQCDGCGKWFHADCLgpplsSFVPNGKWICPVC 48

RING finger, H2 subclass, found in RING finger protein 43 (RNF43) and similar proteins; RNF43 is a transmembrane E3 ubiquitin-protein ligase that plays an important role in frizzled (FZD)-dependent regulation of the Wnt/beta-catenin pathway. It functions as a tumor suppressor that inhibits Wnt/beta-catenin signaling by ubiquitinating FZD receptor and targeting it to the lysosomal pathway for degradation. miR-550a-5p directly targeted the 3'-UTR of gene RNF43 and regulated its expression. Moreover, RNF43 interacts with NEDD-4-like ubiquitin-protein ligase-1 (NEDL1) and regulates p53-mediated transcription. It may also be involved in cell growth control through the interaction with HAP95, a chromatin-associated protein interfacing the nuclear envelope. Mutations of RNF43 have been identified in various tumors, including colorectal cancer (CRC), endometrial cancer, mucinous ovarian tumors, gastric adenocarcinoma, pancreatic ductal adenocarcinoma, liver fluke-associated cholangiocarcinoma, hepatocellular carcinoma, and glioma. RNF43 contains an N-terminal signal peptide, a protease-associated (PA) domain, a transmembrane (TM) domain and a C3H2C3-type RING-H2 finger followed by a long C-terminal region.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*.
gi 115534505 528 CIICREDIdLENGTVQCPRCTEIYHSHCATQWLSQKPTCPKCIFHI 573
Cdd:cd16798    6 CAICLEEF-SEGQELRIISCSHEFHRECVDPWLHQHRTCPLCMFNI 50

RING finger, H2 subclass, found in RING finger protein 167 (RNF167) and similar proteins; RNF167, also known as RING105, is an endosomal/lysosomal E3 ubiquitin-protein ligase involved in alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) ubiquitination. It ubiquitinates AMPA-type glutamate receptor subunit GluA2 and regulates its surface expression, and thus acts as a selective regulator of AMPAR-mediated neurotransmission. It acts as an endosomal membrane protein which ubiquitylates vesicle-associated membrane protein 3 (VAMP3) and regulates endosomal trafficking. Moreover, RNF167 plays a role in the regulation of TSSC5 (tumor-suppressing subchromosomal transferable fragment cDNA, also known as ORCTL2/IMPT1/BWR1A/SLC22A1L), which can function in concert with the ubiquitin-conjugating enzyme UbcH6. RNF167 is widely conserved in metazoans and contains an N-terminal signal peptide, a protease-associated (PA) domain, two transmembrane domains (TM1 and TM2), and a C-terminal C3H2C3-type RING-H2 finger domain followed by a putative PEST sequence.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|...
gi 115534505 528 CIICREDIDlENGTVQCPRCTEIYHSHCATQWLSQ-KPTCPKC 569
Cdd:cd16797    3 CAICLDEYE-EGDKLRVLPCSHAYHSKCVDPWLTQtKKTCPVC 44

RING finger, HC subclass, found in RING finger protein 213 (RNF213) and similar proteins; RNF213, also known as ALK lymphoma oligomerization partner on chromosome 17 or Moyamoya steno-occlusive disease-associated AAA+ and RING finger protein (mysterin), is an intracellular soluble protein that functions as an E3 ubiquitin-protein ligase and AAA+ ATPase, which possibly contributes to vascular development through mechanical processes in the cell. It plays a unique role in endothelial cells for proper gene expression in response to inflammatory signals from the environment. Mutations in RNF213 may be associated with Moyamoya disease (MMD), an idiopathic cerebrovascular occlusive disorder prevalent in East Asia. It also acts as a nuclear marker for acanthomorph phylogeny. RNF213 contains two tandem enzymatically active AAA+ ATPase modules and a C3HC4-type RING-HC finger. It can form a huge ring-shaped oligomeric complex.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*
gi 115534505 525 ESECIICREDIdleNGTVQCPrCTEIYHSHCATQWLSQKPTCPKC 569
Cdd:cd16561    2 EQECSICLEDL---NDPVKLP-CDHVFCEECIRQWLPGQMSCPLC 42

Modified RING-CH finger, H2 subclass (C4HC2H-type), found in the ZNRF family; The ZNRF family includes zinc/RING finger proteins ZNRF1, ZNRF2, and similar proteins. It has been characterized by containing a unique combination of zinc finger-RING finger motifs in the C-terminal region, which is evolutionarily conserved in a wide range of species, including Caenorhabditis elegans and Drosophila. ZNRF proteins function as E3 ubiquitin ligases and are highly expressed in central nervous system (CNS) and peripheral nervous system (PNS) neurons, particularly during development and in adulthood. ZNRF1 and ZNRF2 are differentially localized within the synaptic region. ZNRF1 is associated with synaptic vesicle membranes, whereas ZNRF2 is present in presynaptic plasma membranes. They are N-myrisotoylated and also located in the endosome-lysosome compartment in fibroblasts. ZNRF proteins may play a role in the establishment and maintenance of neuronal transmission and plasticity via their ubiquitin ligase activity, as well as in regulating Ca2+-dependent exocytosis. The RING fingers found in ZNRF proteins are modified as C4HC2H-type RING-CH finger, rather than the typical C4HC3-type RING-CH finger, which is a variant of the RING-H2 finger.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|.
gi 115534505 527 ECIICREDIdLENGTVQCPRCTEIYHSHCATQWLSQKPTCP 567
Cdd:cd16489    1 ECVICLEEL-EAGDTIARLPCLCIYHKKCIDDWFEVNRSCP 40

Modified RING-CH finger, H2 subclass (C4HC2H-type), found in zinc/RING finger protein 1 (ZNRF1) and similar proteins; ZNRF1, also known as Nerve injury-induced gene 283 protein (nin283), or peripheral nerve injury protein (PNIP), is an E3 ubiquitin-protein ligase that is highly expressed in the nervous system during development and is associated with synaptic vesicle membranes. It is N-myrisotoylated and is also located in the endosome-lysosome compartment in fibroblasts, suggesting it may participate in ubiquitin-mediated protein modification. It contains an N-terminal MAGE domain, and a special C-terminal domain that combines a zinc finger and a modified C4HC2H-type RING-CH finger, rather than the typical C4HC3-type RING-CH finger, which is a variant of the RING-H2 finger. Only the RING finger of the zinc finger-RING finger motif is required for its E3 ubiquitin ligase activity. ZNRF1 regulates Schwann cell differentiation by proteasomal degradation of glutamine synthetase (GS). It also mediates regulation of neuritogenesis via interaction with beta-tubulin type 2 (Tubb2). Moreover, ZNRF1 promotes Wallerian degeneration by degrading AKT to induce glycogen synthase kinase-3beta (GSK3B)-dependent CRMP2 phosphorylation. Furthermore, ZNRF1 and its sister protein ZNRF2 regulate the ubiquitous Na+/K+ pump (Na+/K+ATPase). In addition, ZNRF1 may be associated with leukemogenesis of acute lymphoblastic leukemia (ALL) with paired box domain gene 5 (PAX5) alteration.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|..
gi 115534505 527 ECIICREDIDLENGTVQCPrCTEIYHSHCATQWLSQKPTCPK 568
Cdd:cd16694    1 ECVICLEELLQGDTIARLP-CLCIYHKSCIDSWFEVNRSCPE 41