Downstream of tyrosine kinase 4, 5, and 6 proteins phosphotyrosine-binding domain (PTBi); The Dok family adapters are phosphorylated by different protein tyrosine kinases. Dok proteins are involved in processes such as modulation of cell differentiation and proliferation, as well as in control of the cell spreading and migration The Dok protein contains an N-terminal pleckstrin homology (PH) domain followed by a central phosphotyrosine binding (PTB) domain, which has a PH-like fold, and a proline- and tyrosine-rich C-terminal tail. The PH domain binds to acidic phospholids and localizes proteins to the plasma membrane, while the PTB domain mediates protein-protein interactions by binding to phosphotyrosine-containing motifs. The C-terminal part of Dok contains multiple tyrosine phosphorylation sites that serve as potential docking sites for Src homology 2-containing proteins such as ras GTPase-activating protein and Nck, leading to inhibition of ras signaling pathway activation and the c-Jun N-terminal kinase (JNK) and c-Jun activation, respectively. There are 7 mammalian Dok members: Dok-1 to Dok-7. Dok-1 and Dok-2 act as negative regulators of the Ras-Erk pathway downstream of many immunoreceptor-mediated signaling systems, and it is believed that recruitment of p120 rasGAP by Dok-1 and Dok-2 is critical to their negative regulation. Dok-3 is a negative regulator of the activation of JNK and mobilization of Ca2+ in B-cell receptor-mediated signaling, interacting with SHIP-1 and Grb2. Dok-4- 6 play roles in protein tyrosine kinase(PTK)-mediated signaling in neural cells and Dok-7 is the key cytoplasmic activator of MuSK (Muscle-Specific Protein Tyrosine Kinase). PTB domains have a common PH-like fold and are found in various eukaryotic signaling molecules. This domain was initially shown to binds peptides with a NPXY motif with differing requirements for phosphorylation of the tyrosine, although more recent studies have found that some types of PTB domains can bind to peptides lack tyrosine residues altogether. In contrast to SH2 domains, which recognize phosphotyrosine and adjacent carboxy-terminal residues, PTB-domain binding specificity is conferred by residues amino-terminal to the phosphotyrosine. PTB domains are classified into three groups: phosphotyrosine-dependent Shc-like, phosphotyrosine-dependent IRS-like, and phosphotyrosine-independent Dab-like PTB domains. This cd is part of the IRS-like subgroup.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1907186586 133 CEQTDRFNVFLLPCPNLDVYGECKLQITHENIYLWDIHNPRVKLVSWPLCSLRRYGRDATRFTFEAGRMCDAGEGLYTFQ 212
Cdd:cd13164     1 REQNERFNVFLLPSPNLDVYGECLLQITHENIYLWDIHNPRVKLVSWPLCSLRRYGRDSTWFTFEAGRMCDTGEGLFTFQ 80

                          90       100
                  ....*....|....*....|...
gi 1907186586 213 TQEGEQIYQRVHSATLAIAEQHK 235
Cdd:cd13164    81 TREGEQIYQRVHSATLAIAEQHK 103

Downstream of tyrosine kinase 4, 5, and 6 proteins phosphotyrosine-binding domain (PTBi); The Dok family adapters are phosphorylated by different protein tyrosine kinases. Dok proteins are involved in processes such as modulation of cell differentiation and proliferation, as well as in control of the cell spreading and migration The Dok protein contains an N-terminal pleckstrin homology (PH) domain followed by a central phosphotyrosine binding (PTB) domain, which has a PH-like fold, and a proline- and tyrosine-rich C-terminal tail. The PH domain binds to acidic phospholids and localizes proteins to the plasma membrane, while the PTB domain mediates protein-protein interactions by binding to phosphotyrosine-containing motifs. The C-terminal part of Dok contains multiple tyrosine phosphorylation sites that serve as potential docking sites for Src homology 2-containing proteins such as ras GTPase-activating protein and Nck, leading to inhibition of ras signaling pathway activation and the c-Jun N-terminal kinase (JNK) and c-Jun activation, respectively. There are 7 mammalian Dok members: Dok-1 to Dok-7. Dok-1 and Dok-2 act as negative regulators of the Ras-Erk pathway downstream of many immunoreceptor-mediated signaling systems, and it is believed that recruitment of p120 rasGAP by Dok-1 and Dok-2 is critical to their negative regulation. Dok-3 is a negative regulator of the activation of JNK and mobilization of Ca2+ in B-cell receptor-mediated signaling, interacting with SHIP-1 and Grb2. Dok-4- 6 play roles in protein tyrosine kinase(PTK)-mediated signaling in neural cells and Dok-7 is the key cytoplasmic activator of MuSK (Muscle-Specific Protein Tyrosine Kinase). PTB domains have a common PH-like fold and are found in various eukaryotic signaling molecules. This domain was initially shown to binds peptides with a NPXY motif with differing requirements for phosphorylation of the tyrosine, although more recent studies have found that some types of PTB domains can bind to peptides lack tyrosine residues altogether. In contrast to SH2 domains, which recognize phosphotyrosine and adjacent carboxy-terminal residues, PTB-domain binding specificity is conferred by residues amino-terminal to the phosphotyrosine. PTB domains are classified into three groups: phosphotyrosine-dependent Shc-like, phosphotyrosine-dependent IRS-like, and phosphotyrosine-independent Dab-like PTB domains. This cd is part of the IRS-like subgroup.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1907186586 133 CEQTDRFNVFLLPCPNLDVYGECKLQITHENIYLWDIHNPRVKLVSWPLCSLRRYGRDATRFTFEAGRMCDAGEGLYTFQ 212
Cdd:cd13164     1 REQNERFNVFLLPSPNLDVYGECLLQITHENIYLWDIHNPRVKLVSWPLCSLRRYGRDSTWFTFEAGRMCDTGEGLFTFQ 80

                          90       100
                  ....*....|....*....|...
gi 1907186586 213 TQEGEQIYQRVHSATLAIAEQHK 235
Cdd:cd13164    81 TREGEQIYQRVHSATLAIAEQHK 103

Phosphotyrosine-binding domain (IRS1-like);

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1907186586  131 VQCEQTDRFNVFLLPCPNldvYGECKLQITHENIYLWDIHNPRVKLVSWPLCSLRRYGRDATRFTFEAGRMCDAGEGLYT 210
Cdd:smart00310   1 KQFWVTIRKTEGLERCPL---SGSYRLRLTSEELVLWRGLNPRVELVVWPLLSLRRYGRDKVFFFFEAGRRCVSGPGEFT 77

                           90       100
                   ....*....|....*....|..
gi 1907186586  211 FQTQEGEQIYQRVHSATLAIAE 232
Cdd:smart00310  78 FQTVVAQEIFQLVLEAMQAQKN 99

Pleckstrin homology domain; Domain commonly found in eukaryotic signalling proteins. The domain family possesses multiple functions including the abilities to bind inositol phosphates, and various proteins. PH domains have been found to possess inserted domains (such as in PLC gamma, syntrophins) and to be inserted within other domains. Mutations in Brutons tyrosine kinase (Btk) within its PH domain cause X-linked agammaglobulinaemia (XLA) in patients. Point mutations cluster into the positively charged end of the molecule around the predicted binding site for phosphatidylinositol lipids.

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1907186586    8 IVKQGYVKMKS-RKLGIYRRCWLVFRkssskgPQRLEKYPDEKSVCLRGCPKVTEISNVKCVTRLPKET--KRQAVAIIF 84
Cdd:smart00233   1 VIKEGWLYKKSgGGKKSWKKRYFVLF------NSTLLYYKSKKDKKSYKPKGSIDLSGCTVREAPDPDSskKPHCFEIKT 74

                           90       100
                   ....*....|....*....|...
gi 1907186586   85 TDDSARTFTCDSELEAEEWYKTL 107
Cdd:smart00233  75 SDRKTLLLQAESEEEREKWVEAL 97

Downstream of tyrosine kinase 4, 5, and 6 proteins phosphotyrosine-binding domain (PTBi); The Dok family adapters are phosphorylated by different protein tyrosine kinases. Dok proteins are involved in processes such as modulation of cell differentiation and proliferation, as well as in control of the cell spreading and migration The Dok protein contains an N-terminal pleckstrin homology (PH) domain followed by a central phosphotyrosine binding (PTB) domain, which has a PH-like fold, and a proline- and tyrosine-rich C-terminal tail. The PH domain binds to acidic phospholids and localizes proteins to the plasma membrane, while the PTB domain mediates protein-protein interactions by binding to phosphotyrosine-containing motifs. The C-terminal part of Dok contains multiple tyrosine phosphorylation sites that serve as potential docking sites for Src homology 2-containing proteins such as ras GTPase-activating protein and Nck, leading to inhibition of ras signaling pathway activation and the c-Jun N-terminal kinase (JNK) and c-Jun activation, respectively. There are 7 mammalian Dok members: Dok-1 to Dok-7. Dok-1 and Dok-2 act as negative regulators of the Ras-Erk pathway downstream of many immunoreceptor-mediated signaling systems, and it is believed that recruitment of p120 rasGAP by Dok-1 and Dok-2 is critical to their negative regulation. Dok-3 is a negative regulator of the activation of JNK and mobilization of Ca2+ in B-cell receptor-mediated signaling, interacting with SHIP-1 and Grb2. Dok-4- 6 play roles in protein tyrosine kinase(PTK)-mediated signaling in neural cells and Dok-7 is the key cytoplasmic activator of MuSK (Muscle-Specific Protein Tyrosine Kinase). PTB domains have a common PH-like fold and are found in various eukaryotic signaling molecules. This domain was initially shown to binds peptides with a NPXY motif with differing requirements for phosphorylation of the tyrosine, although more recent studies have found that some types of PTB domains can bind to peptides lack tyrosine residues altogether. In contrast to SH2 domains, which recognize phosphotyrosine and adjacent carboxy-terminal residues, PTB-domain binding specificity is conferred by residues amino-terminal to the phosphotyrosine. PTB domains are classified into three groups: phosphotyrosine-dependent Shc-like, phosphotyrosine-dependent IRS-like, and phosphotyrosine-independent Dab-like PTB domains. This cd is part of the IRS-like subgroup.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1907186586 133 CEQTDRFNVFLLPCPNLDVYGECKLQITHENIYLWDIHNPRVKLVSWPLCSLRRYGRDATRFTFEAGRMCDAGEGLYTFQ 212
Cdd:cd13164     1 REQNERFNVFLLPSPNLDVYGECLLQITHENIYLWDIHNPRVKLVSWPLCSLRRYGRDSTWFTFEAGRMCDTGEGLFTFQ 80

                          90       100
                  ....*....|....*....|...
gi 1907186586 213 TQEGEQIYQRVHSATLAIAEQHK 235
Cdd:cd13164    81 TREGEQIYQRVHSATLAIAEQHK 103

Phosphotyrosine-binding domain (IRS1-like);

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1907186586  131 VQCEQTDRFNVFLLPCPNldvYGECKLQITHENIYLWDIHNPRVKLVSWPLCSLRRYGRDATRFTFEAGRMCDAGEGLYT 210
Cdd:smart00310   1 KQFWVTIRKTEGLERCPL---SGSYRLRLTSEELVLWRGLNPRVELVVWPLLSLRRYGRDKVFFFFEAGRRCVSGPGEFT 77

                           90       100
                   ....*....|....*....|..
gi 1907186586  211 FQTQEGEQIYQRVHSATLAIAE 232
Cdd:smart00310  78 FQTVVAQEIFQLVLEAMQAQKN 99

Downstream of tyrosine kinase 1, 2, and 3 proteins phosphotyrosine-binding domain (PTBi); The Dok family adapters are phosphorylated by different protein tyrosine kinases. Dok proteins are involved in processes such as modulation of cell differentiation and proliferation, as well as in control of the cell spreading and migration The Dok protein contains an N-terminal pleckstrin homology (PH) domain followed by a central phosphotyrosine binding (PTB) domain, which has a PH-like fold, and a proline- and tyrosine-rich C-terminal tail. The PH domain is binds to acidic phospholids and localizes proteins to the plasma membrane, while the PTB domain mediates protein-protein interactions by binding to phosphotyrosine-containing motifs. The C-terminal part of Dok contains multiple tyrosine phosphorylation sites that serve as potential docking sites for Src homology 2-containing proteins such as ras GTPase-activating protein and Nck, leading to inhibition of ras signaling pathway activation and the c-Jun N-terminal kinase (JNK) and c-Jun activation, respectively. There are 7 mammalian Dok members: Dok-1 to Dok-7. Dok-1 and Dok-2 act as negative regulators of the Ras-Erk pathway downstream of many immunoreceptor-mediated signaling systems, and it is believed that recruitment of p120 rasGAP by Dok-1 and Dok-2 is critical to their negative regulation. Dok-3 is a negative regulator of the activation of JNK and mobilization of Ca2+ in B-cell receptor-mediated signaling, interacting with SHIP-1 and Grb2. Dok-4- 6 play roles in protein tyrosine kinase(PTK)-mediated signaling in neural cells and Dok-7 is the key cytoplasmic activator of MuSK (Muscle-Specific Protein Tyrosine Kinase). PTB domains have a common PH-like fold and are found in various eukaryotic signaling molecules. This domain was initially shown to binds peptides with a NPXY motif with differing requirements for phosphorylation of the tyrosine, although more recent studies have found that some types of PTB domains can bind to peptides lack tyrosine residues altogether. In contrast to SH2 domains, which recognize phosphotyrosine and adjacent carboxy-terminal residues, PTB-domain binding specificity is conferred by residues amino-terminal to the phosphotyrosine. PTB domains are classified into three groups: phosphotyrosine-dependent Shc-like, phosphotyrosine-dependent IRS-like, and phosphotyrosine-independent Dab-like PTB domains. This cd is part of the IRS-like subgroup.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1907186586 153 GECKLQITHENIYLWDIHNPRVkLVSWPLCSLRRYGRDATRFTFEAGRMCDAGEGLYTFQTQEGEQIYQRVHSatlAIAE 232
Cdd:cd01203    22 GSYLLRAGQDALELLDPQTKKP-LYSWPYRFLRRFGRDKVMFSFEAGRRCDSGEGLFTFETPQGNEIFQAVEA---AIAA 97

                  .
gi 1907186586 233 Q 233
Cdd:cd01203    98 Q 98

Insulin receptor substrate (IRS) pleckstrin homology (PH) domain; Insulin receptor substrate (IRS) molecules are mediators in insulin signaling and play a role in maintaining basic cellular functions such as growth and metabolism. They act as docking proteins between the insulin receptor and a complex network of intracellular signaling molecules containing Src homology 2 (SH2) domains. Four members (IRS-1, IRS-2, IRS-3, IRS-4) of this family have been identified that differ as to tissue distribution, subcellular localization, developmental expression, binding to the insulin receptor, and interaction with SH2 domain-containing proteins. IRS molecules have an N-terminal PH domain, followed by an IRS-like PTB domain which has a PH-like fold. PH domains have diverse functions, but in general are involved in targeting proteins to the appropriate cellular location or in the interaction with a binding partner. They share little sequence conservation, but all have a common fold, which is electrostatically polarized. Less than 10% of PH domains bind phosphoinositide phosphates (PIPs) with high affinity and specificity. PH domains are distinguished from other PIP-binding domains by their specific high-affinity binding to PIPs with two vicinal phosphate groups: PtdIns(3,4)P2, PtdIns(4,5)P2 or PtdIns(3,4,5)P3 which results in targeting some PH domain proteins to the plasma membrane. A few display strong specificity in lipid binding. Any specificity is usually determined by loop regions or insertions in the N-terminus of the domain, which are not conserved across all PH domains. PH domains are found in cellular signaling proteins such as serine/threonine kinase, tyrosine kinases, regulators of G-proteins, endocytotic GTPases, adaptors, as well as cytoskeletal associated molecules and in lipid associated enzymes.cytoskeletal associated molecules, and in lipid associated enzymes.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1907186586   6 NDIVKQGYVkmksRKLGIYRRCWLVFRKSSSKGPQRLEKYPDEK----------SVCLRGCPKVTEISNvkcvtrlpkeT 75
Cdd:cd01257     1 TDVRKSGYL----KKLKTMRKRYFVLRAESHGGPARLEYYENEKkfrrnaepkrVIPLSSCFNINKRAD----------A 66

                          90       100       110
                  ....*....|....*....|....*....|..
gi 1907186586  76 KRQAVAIIFTDDSARTFTCDSELEAEEWYKTL 107
Cdd:cd01257    67 KHKHLIALYTKDECFGLVAESEEEQDEWYQAL 98

Pleckstrin homology (PH) domain; PH domains have diverse functions, but in general are involved in targeting proteins to the appropriate cellular location or in the interaction with a binding partner. They share little sequence conservation, but all have a common fold, which is electrostatically polarized. Less than 10% of PH domains bind phosphoinositide phosphates (PIPs) with high affinity and specificity. PH domains are distinguished from other PIP-binding domains by their specific high-affinity binding to PIPs with two vicinal phosphate groups: PtdIns(3,4)P2, PtdIns(4,5)P2 or PtdIns(3,4,5)P3 which results in targeting some PH domain proteins to the plasma membrane. A few display strong specificity in lipid binding. Any specificity is usually determined by loop regions or insertions in the N-terminus of the domain, which are not conserved across all PH domains. PH domains are found in cellular signaling proteins such as serine/threonine kinase, tyrosine kinases, regulators of G-proteins, endocytotic GTPases, adaptors, as well as cytoskeletal associated molecules and in lipid associated enzymes.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1907186586  10 KQGYV-KMKSRKLGIYRRCWLVFRKSsskgpqRLEKYPDEKSVCLRGCPKVtEISNVKCVTRLPKETKRQAVAIIFTDDS 88
Cdd:cd00821     1 KEGYLlKRGGGGLKSWKKRWFVLFEG------VLLYYKSKKDSSYKPKGSI-PLSGILEVEEVSPKERPHCFELVTPDGR 73

                          90
                  ....*....|....*....
gi 1907186586  89 ARTFTCDSELEAEEWYKTL 107
Cdd:cd00821    74 TYYLQADSEEERQEWLKAL 92

Downstream of tyrosine kinase 7 phosphotyrosine-binding domain (PTBi); The Dok family adapters are phosphorylated by different protein tyrosine kinases. Dok proteins are involved in processes such as modulation of cell differentiation and proliferation, as well as in control of the cell spreading and migration The Dok protein contains an N-terminal pleckstrin homology (PH) domain followed by a central phosphotyrosine binding (PTB) domain, which has a PH-like fold, and a proline- and tyrosine-rich C-terminal tail. The PH domain is binds to acidic phospholids and localizes proteins to the plasma membrane, while the PTB domain mediates protein-protein interactions by binding to phosphotyrosine-containing motifs. The C-terminal part of Dok contains multiple tyrosine phosphorylation sites that serve as potential docking sites for Src homology 2-containing proteins such as ras GTPase-activating protein and Nck, leading to inhibition of ras signaling pathway activation and the c-Jun N-terminal kinase (JNK) and c-Jun activation, respectively. There are 7 mammalian Dok members: Dok-1 to Dok-7. Dok-1 and Dok-2 act as negative regulators of the Ras-Erk pathway downstream of many immunoreceptor-mediated signaling systems, and it is believed that recruitment of p120 rasGAP by Dok-1 and Dok-2 is critical to their negative regulation. Dok-3 is a negative regulator of the activation of JNK and mobilization of Ca2+ in B-cell receptor-mediated signaling, interacting with SHIP-1 and Grb2. Dok-4- 6 play roles in protein tyrosine kinase(PTK)-mediated signaling in neural cells and Dok-7 is the key cytoplasmic activator of MuSK (Muscle-Specific Protein Tyrosine Kinase). PTB domains have a common PH-like fold and are found in various eukaryotic signaling molecules. This domain was initially shown to binds peptides with a NPXY motif with differing requirements for phosphorylation of the tyrosine, although more recent studies have found that some types of PTB domains can bind to peptides lack tyrosine residues altogether. In contrast to SH2 domains, which recognize phosphotyrosine and adjacent carboxy-terminal residues, PTB-domain binding specificity is conferred by residues amino-terminal to the phosphotyrosine. PTB domains are classified into three groups: phosphotyrosine-dependent Shc-like, phosphotyrosine-dependent IRS-like, and phosphotyrosine-independent Dab-like PTB domains. This cd is part of the IRS-like subgroup.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|.
gi 1907186586 179 WPLCSLRRYGRDATRFTFEAGRMCDAGEGLYTFQTQEGEQI 219
Cdd:cd13165    45 WKLSDLRRYGAVPGGFIFEGGTRCGKWAGVFFLSTEEGEQI 85

Autophagy-related protein 26/Sterol 3-beta-glucosyltransferase Pleckstrin homology (PH) domain, repeat 1; ATG26 (also called UGT51/UDP-glycosyltransferase 51), a member of the glycosyltransferase 28 family, resulting in the biosynthesis of sterol glucoside. ATG26 in decane metabolism and autophagy. There are 32 known autophagy-related (ATG) proteins, 17 are components of the core autophagic machinery essential for all autophagy-related pathways and 15 are the additional components required only for certain pathways or species. The core autophagic machinery includes 1) the ATG9 cycling system (ATG1, ATG2, ATG9, ATG13, ATG18, and ATG27), 2) the phosphatidylinositol 3-kinase complex (ATG6/VPS30, ATG14, VPS15, and ATG34), and 3) the ubiquitin-like protein system (ATG3, ATG4, ATG5, ATG7, ATG8, ATG10, ATG12, and ATG16). Less is known about how the core machinery is adapted or modulated with additional components to accommodate the nonselective sequestration of bulk cytosol (autophagosome formation) or selective sequestration of specific cargos (Cvt vesicle, pexophagosome, or bacteria-containing autophagosome formation). The pexophagosome-specific additions include the ATG30-ATG11-ATG17 receptor-adaptors complex, the coiled-coil protein ATG25, and the sterol glucosyltransferase ATG26. ATG26 is necessary for the degradation of medium peroxisomes. It contains 2 GRAM domains and a single PH domain. PH domains are only found in eukaryotes. They share little sequence conservation, but all have a common fold, which is electrostatically polarized. PH domains also have diverse functions. They are often involved in targeting proteins to the plasma membrane, but few display strong specificity in lipid binding. Any specificity is usually determined by loop regions or insertions in the N-terminus of the domain, which are not conserved across all PH domains. PH domains are found in cellular signaling proteins such as serine/threonine kinase, tyrosine kinases, regulators of G-proteins, endocytotic GTPases, adaptors, as well as cytoskeletal associated molecules and in lipid associated enzymes.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1907186586   6 NDIVKQGYVKMKSRKLGIYRRCWLVFRKSSskgpqrLEKYPDEK-------SVCLRgcpKVTEISNVKCVTRLPKETKrq 78
Cdd:cd13215    19 GAVIKSGYLSKRSKRTLRYTRYWFVLKGDT------LSWYNSSTdlyfpagTIDLR---YATSIELSKSNGEATTSFK-- 87

                          90       100
                  ....*....|....*....|....*....
gi 1907186586  79 avaiIFTDDSARTFTCDSELEAEEWYKTL 107
Cdd:cd13215    88 ----IVTNSRTYKFKADSETSADEWVKAL 112

Bud4 Pleckstrin homology (PH) domain; Bud4 is an anillin-like yeast protein involved in the formation and the disassembly of the double ring structure formed by the septins during cytokinesis. Bud4 acts with Bud3 and and in parallel with septin phosphorylation by the p21-activated kinase Cla4 and the septin-dependent kinase Gin4. Bud4 is regulated by the cyclin-dependent protein kinase Cdk1, the master regulator of cell cycle progression. Bud4 contains an anillin-like domain followed by a PH domain. In addition there are two consensus Cdk phosphorylation sites: one at the N-terminus and one right before the C-terminal PH domain. Anillins also have C-terminal PH domains. PH domains have diverse functions, but in general are involved in targeting proteins to the appropriate cellular location or in the interaction with a binding partner. They share little sequence conservation, but all have a common fold, which is electrostatically polarized. Less than 10% of PH domains bind phosphoinositide phosphates (PIPs) with high affinity and specificity. PH domains are distinguished from other PIP-binding domains by their specific high-affinity binding to PIPs with two vicinal phosphate groups: PtdIns(3,4)P2, PtdIns(4,5)P2 or PtdIns(3,4,5)P3 which results in targeting some PH domain proteins to the plasma membrane. A few display strong specificity in lipid binding. Any specificity is usually determined by loop regions or insertions in the N-terminus of the domain, which are not conserved across all PH domains. PH domains are found in cellular signaling proteins such as serine/threonine kinase, tyrosine kinases, regulators of G-proteins, endocytotic GTPases, adaptors, as well as cytoskeletal associated molecules and in lipid associated enzymes.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|.
gi 1907186586  58 KVTEISNVKCVTRLPKETKR---------QAVAIIFTDDSARTFTCDSELEAEEWYKTLSV 109
Cdd:cd13278    65 KVVDVVDDDDARERTSSFKRnftdlvlfeECFRLVFANGEVIDFYADSKEEKADWYSKLKE 125