Mpr1p, Pad1p N-terminal (MPN) domains; MPN (also known as Mov34, PAD-1, JAMM, JAB, MPN+) domains are found in the N-terminal termini of proteins with a variety of functions; they are components of the proteasome regulatory subunits, the signalosome (CSN), eukaryotic translation initiation factor 3 (eIF3) complexes, and regulators of transcription factors. These domains are isopeptidases that release ubiquitin from ubiquitinated proteins (thus having deubiquitinating (DUB) activity) that are tagged for degradation. Catalytically active MPN domains contain a metalloprotease signature known as the JAB1/MPN/Mov34 metalloenzyme (JAMM) motif. For example, Rpn11 (also known as POH1 or PSMD14), a subunit of the 19S proteasome lid is involved in the ATP-dependent degradation of ubiquitinated proteins, contains the conserved JAMM motif involved in zinc ion coordination. Poh1 is a regulator of c-Jun, an important regulator of cell proliferation, differentiation, survival and death. JAB1 is a component of the COP9 signalosome (CSN), a regulatory particle of the ubiquitin (Ub)/26S proteasome system occurring in all eukaryotic cells; it cleaves the ubiquitin-like protein NEDD8 from the cullin subunit of the SCF (Skp1, Cullins, F-box proteins) family of E3 ubiquitin ligases. AMSH (associated molecule with the SH3 domain of STAM, also known as STAMBP), a member of JAMM/MPN+ deubiquitinases (DUBs), specifically cleaves Lys 63-linked polyubiquitin (poly-Ub) chains, thus facilitating the recycling and subsequent trafficking of receptors to the cell surface. Similarly, BRCC36, part of the nuclear complex that includes BRCA1 protein and is targeted to DNA damage foci after irradiation, specifically disassembles K63-linked polyUb. BRCC36 is aberrantly expressed in sporadic breast tumors, indicative of a potential role in the pathogenesis of the disease. Some variants of the JAB1/MPN domains lack key residues in their JAMM motif and are unable to coordinate a metal ion. Comparisons of key catalytic and metal binding residues explain why the MPN-containing proteins Mov34/PSMD7, Rpn8, CSN6, Prp8p, and the translation initiation factor 3 subunits f (p47) and h (p40) do not show catalytic isopeptidase activity. It has been proposed that the MPN domain in these proteins has a primarily structural function.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 767913672 254 LRHVVVPGRLCPQFLQLASANTARGVETCGILCGKLMRNEFTITHVLIPKQSAGSDYCNTENEEELFLIQDQQGLITLGW 333
Cdd:cd08066    1 LRQVVVPADLMDKFLQLAEPNTSRNLETCGILCGKLSNNAFFITHLIIPKQSGTSDSCQTTNEEELFDFQDQHDLITLGW 80

                 ..
gi 767913672 334 IH 335
Cdd:cd08066   81 IH 82

Mov34/MPN/PAD-1 family; AMSH (associated molecule with the Src homology 3 domain (SH3) of STAM (signal-transducing adapter molecule, also known as STAMBP)) and AMSH-like proteins (AMSH-LP) are members of JAMM/MPN+ deubiquitinases (DUBs), with Zn2+-dependent ubiquitin isopeptidase activity. AMSH specifically cleaves Lys 63 and not Lys48-linked polyubiquitin (poly-Ub) chains, thus facilitating the recycling and subsequent trafficking of receptors to the cell surface. AMSH and AMSH-LP are anchored on the early endosomal membrane via interaction with the clathrin coat. AMSH shares a common SH3-binding site with another endosomal DUB, UBPY (ubiquitin-specific protease Y; also known as USP8), the latter being a cysteine protease that does not discriminate between Lys48 and Lys63-linked ubiquitin. AMSH is involved in the degradation of EGF receptor (EGFR) and possibly other ubiquitinated endocytosed proteins. AMSH also interacts with CHMP1, CHMP2, and CHMP3 proteins, all of which are components of ESCRT-III, suggested to be required for EGFR down-regulation. The function of AMSH-LP has not been elucidated; however, it exhibits two fundamentally distinct features from AMSH: first, there is a substitution in the critical amino acid residue in the SH3-binding motif (SBM) in the human AMSH-LP, but not in its mouse ortholog, and lacks STAM-binding ability; second, AMSH-LP lacks the ability to interact with CHMP proteins. It is therefore likely that AMSH and AMSH-LP play different roles on early endosomes.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 767913672 254 LRHVVVPGRLCPQFLQLASANTARGVETCGILCGKLMRNEFTITHVLIPKQSAGSDYCNTENEEELFLIQDQQGLITLGW 333
Cdd:cd08066    1 LRQVVVPADLMDKFLQLAEPNTSRNLETCGILCGKLSNNAFFITHLIIPKQSGTSDSCQTTNEEELFDFQDQHDLITLGW 80

                 ..
gi 767913672 334 IH 335
Cdd:cd08066   81 IH 82

JAB1/Mov34/MPN/PAD-1 ubiquitin protease; Members of this family are found in proteasome regulatory subunits, eukaryotic initiation factor 3 (eIF3) subunits and regulators of transcription factors. This family is also known as the MPN domain and PAD-1-like domain, JABP1 domain or JAMM domain. These are metalloenzymes that function as the ubiquitin isopeptidase/ deubiquitinase in the ubiquitin-based signalling and protein turnover pathways in eukaryotes. Versions of the domain in prokaryotic cognates of the ubiquitin-modification pathway are shown to have a similar role, and the archael protein from Haloferax volcanii is found to cleave ubiquitin-like small archaeal modifier proteins (SAMP1/2) from protein conjugates.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 767913672  252 DGLRHVVVPGRLCPQFLQLASANTARGVETCGILCGKLMRNEFT-ITHVLIPKQSAGSDYCNTENEEELF-------LIQ 323
Cdd:pfam01398   1 SSVRTVIIHPLVLLKILDHANRGGKIGEEVMGVLLGKLEGDGTIeITNSFALPQEETEDDVNAVALDQEYmenmhemLKK 80

                          90
                  ....*....|..
gi 767913672  324 DQQGLITLGWIH 335
Cdd:pfam01398  81 VNRKEEVVGWYH 92

Mov34/MPN/PAD-1 family; AMSH (associated molecule with the Src homology 3 domain (SH3) of STAM (signal-transducing adapter molecule, also known as STAMBP)) and AMSH-like proteins (AMSH-LP) are members of JAMM/MPN+ deubiquitinases (DUBs), with Zn2+-dependent ubiquitin isopeptidase activity. AMSH specifically cleaves Lys 63 and not Lys48-linked polyubiquitin (poly-Ub) chains, thus facilitating the recycling and subsequent trafficking of receptors to the cell surface. AMSH and AMSH-LP are anchored on the early endosomal membrane via interaction with the clathrin coat. AMSH shares a common SH3-binding site with another endosomal DUB, UBPY (ubiquitin-specific protease Y; also known as USP8), the latter being a cysteine protease that does not discriminate between Lys48 and Lys63-linked ubiquitin. AMSH is involved in the degradation of EGF receptor (EGFR) and possibly other ubiquitinated endocytosed proteins. AMSH also interacts with CHMP1, CHMP2, and CHMP3 proteins, all of which are components of ESCRT-III, suggested to be required for EGFR down-regulation. The function of AMSH-LP has not been elucidated; however, it exhibits two fundamentally distinct features from AMSH: first, there is a substitution in the critical amino acid residue in the SH3-binding motif (SBM) in the human AMSH-LP, but not in its mouse ortholog, and lacks STAM-binding ability; second, AMSH-LP lacks the ability to interact with CHMP proteins. It is therefore likely that AMSH and AMSH-LP play different roles on early endosomes.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 767913672 254 LRHVVVPGRLCPQFLQLASANTARGVETCGILCGKLMRNEFTITHVLIPKQSAGSDYCNTENEEELFLIQDQQGLITLGW 333
Cdd:cd08066    1 LRQVVVPADLMDKFLQLAEPNTSRNLETCGILCGKLSNNAFFITHLIIPKQSGTSDSCQTTNEEELFDFQDQHDLITLGW 80

                 ..
gi 767913672 334 IH 335
Cdd:cd08066   81 IH 82

Mpr1p, Pad1p N-terminal (MPN) domains with catalytic isopeptidase activity (metal-binding); eukaryotic; This family contains eukaryotic MPN (also known as Mov34, PAD-1, JAMM, JAB, MPN+) domains found in proteins with a variety of functions, including AMSH (associated molecule with the Src homology 3 domain (SH3) of STAM), H2A-DUB (histone H2A deubiquitinase), BRCC36 (BRCA1/BRCA2-containing complex subunit 36), as well as Rpn11 (regulatory particle number 11) and CSN5 (COP9 signalosome complex subunit 5). These domains contain the signature JAB1/MPN/Mov34 metalloenzyme (JAMM) motif, EXnHS/THX7SXXD, which is involved in zinc ion coordination and provides the active site for isopeptidase activity. Rpn11 is responsible for substrate deubiquitination during proteasomal degradation. It is essential for maintaining a correct cell cycle and normal mitochondrial morphology and physiology. CSN5 is critical for nuclear export and the degradation of several tumor suppressor proteins, including p53, p27, and Smad4. Over-expression of CSN5 has been implicated in cancer initiation and progression. AMSH specifically cleaves Lys 63 and not Lys48-linked polyubiquitin (poly-Ub) chains, thus facilitating the recycling and subsequent trafficking of receptors to the cell surface. It is involved in the degradation of EGF receptor (EGFR) and possibly other ubiquitinated endocytosed proteins. BRCC36 is part of the BRCA1/BRCA2/BARD1-containing nuclear complex that displays an E3 ubiquitin ligase activity; it is targeted to DNA damage foci after irradiation. 2A-DUB is specific for monoubiquitinated H2A (uH2A), regulating transcription by coordinating histone acetylation and deubiquitination, and destabilizing the association of linker histone H1 with nucleosomes. It is a positive regulator of androgen receptor (AR) transactivation activity on a reporter gene and serves as a marker in prostate tumors.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 767913672 263 LCPQFLQLASANTarGVETCGILCGKLMRNEFTITHVLIPKQSAGSDYCNTENEEELFLIQDQQGLITLGWIHA 336
Cdd:cd08058    2 ALLKMLQHAESNT--GIEVMGLLCGELTHNEFTDKHVIVPKQSAGPDSCTGENVEELFNVQTGRPLLVVGWYHS 73

JAB1/Mov34/MPN/PAD-1 ubiquitin protease; Members of this family are found in proteasome regulatory subunits, eukaryotic initiation factor 3 (eIF3) subunits and regulators of transcription factors. This family is also known as the MPN domain and PAD-1-like domain, JABP1 domain or JAMM domain. These are metalloenzymes that function as the ubiquitin isopeptidase/ deubiquitinase in the ubiquitin-based signalling and protein turnover pathways in eukaryotes. Versions of the domain in prokaryotic cognates of the ubiquitin-modification pathway are shown to have a similar role, and the archael protein from Haloferax volcanii is found to cleave ubiquitin-like small archaeal modifier proteins (SAMP1/2) from protein conjugates.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 767913672  252 DGLRHVVVPGRLCPQFLQLASANTARGVETCGILCGKLMRNEFT-ITHVLIPKQSAGSDYCNTENEEELF-------LIQ 323
Cdd:pfam01398   1 SSVRTVIIHPLVLLKILDHANRGGKIGEEVMGVLLGKLEGDGTIeITNSFALPQEETEDDVNAVALDQEYmenmhemLKK 80

                          90
                  ....*....|..
gi 767913672  324 DQQGLITLGWIH 335
Cdd:pfam01398  81 VNRKEEVVGWYH 92