241 human active and 13 inactive phosphatases in total;
194 phosphatases have substrate data;
336 protein substrates;
83 non-protein substrates;
1215 dephosphorylation interactions;
299 KEGG pathways;
876 Reactome pathways;
last scientific update: 11 Mar, 2019
last maintenance update: 01 Sep, 2023
Cell junction, adherens junction Cytoplasm, cytoskeleton Cellprojection, lamellipodium Cellprojection, ruffle membrane Cytoplasm Cell membrane Note=Associated with the microtubulenetwork at the growing distal tip of microtubules(PubMed:19632184) Accumulates in the lamellipodium and rufflemembrane in response to hepatocyte growth factor (HGF) treatment(PubMed:19151759) The MEMO1-RHOA-DIAPH1 signaling pathwaycontrols localization of the phosphorylated form to the cellmembrane (PubMed:20937854)
Function (UniProt annotation)
Tumor suppressor Promotes rapid degradation of CTNNB1and participates in Wnt signaling as a negative regulator APCactivity is correlated with its phosphorylation state Activatesthe GEF activity of SPATA13 and ARHGEF4 Plays a role inhepatocyte growth factor (HGF)-induced cell migration Requiredfor MMP9 up-regulation via the JNK signaling pathway in colorectaltumor cells Acts as a mediator of ERBB2-dependent stabilizationof microtubules at the cell cortex It is required for thelocalization of MACF1 to the cell membrane and this localizationof MACF1 is critical for its function in microtubulestabilization
Wnt proteins are secreted morphogens that are required for basic developmental processes, such as cell-fate specification, progenitor-cell proliferation and the control of asymmetric cell division, in many different species and organs. There are at least three different Wnt pathways: the canonical pathway, the planar cell polarity (PCP) pathway and the Wnt/Ca2+ pathway. In the canonical Wnt pathway, the major effect of Wnt ligand binding to its receptor is the stabilization of cytoplasmic beta-catenin through inhibition of the bea-catenin degradation complex. Beta-catenin is then free to enter the nucleus and activate Wnt-regulated genes through its interaction with TCF (T-cell factor) family transcription factors and concomitant recruitment of coactivators. Planar cell polarity (PCP) signaling leads to the activation of the small GTPases RHOA (RAS homologue gene-family member A) and RAC1, which activate the stress kinase JNK (Jun N-terminal kinase) and ROCK (RHO-associated coiled-coil-containing protein kinase 1) and leads to remodelling of the cytoskeleton and changes in cell adhesion and motility. WNT-Ca2+ signalling is mediated through G proteins and phospholipases and leads to transient increases in cytoplasmic free calcium that subsequently activate the kinase PKC (protein kinase C) and CAMKII (calcium calmodulin mediated kinase II) and the phosphatase calcineurin.
Hippo signaling is an evolutionarily conserved signaling pathway that controls organ size from flies to humans. In humans and mice, the pathway consists of the MST1 and MST2 kinases, their cofactor Salvador and LATS1 and LATS2. In response to high cell densities, activated LATS1/2 phosphorylates the transcriptional coactivators YAP and TAZ, promoting its cytoplasmic localization, leading to cell apoptosis and restricting organ size overgrowth. When the Hippo pathway is inactivated at low cell density, YAP/TAZ translocates into the nucleus to bind to the transcription enhancer factor (TEAD/TEF) family of transcriptional factors to promote cell growth and proliferation. YAP/TAZ also interacts with other transcriptional factors or signaling molecules, by which Hippo pathway-mediated processes are interconnected with those of other key signaling cascades, such as those mediated by TGF-beta and Wnt growth factors.
Pluripotent stem cells (PSCs) are basic cells with an indefinite self-renewal capacity and the potential to generate all the cell types of the three germinal layers. The types of PSCs known to date include embryonic stem (ES) and induced pluripotent stem (iPS) cells. ES cells are derived from the inner cell mass (ICM) of blastocyst-stage embryos. iPS cells are generated by reprogramming somatic cells back to pluripotent state with defined reprogramming factors, Oct4, Sox2, Klf4 and c-Myc (also known as Yamanaka factors). PSCs including ES cells and iPS cells are categorized into two groups by their morphology, gene expression profile and external signal dependence. Conventional mouse-type ES/iPS cells are called 'naive state' cells. They are mainly maintained under the control of LIF and BMP signaling. On the other hand, human-type ES/iPS cells, which are in need of Activin and FGF signaling, are termed 'primed state'. However, these signaling pathways converge towards the activation of a core transcriptional network that is similar in both groups and involves OCt4, Nanog and Sox2. The three transcription factors and their downstream target genes coordinately promote self-renewal and pluripotency.
Cushing syndrome (CS) is a rare disorder resulting from prolonged exposure to excess glucocorticoids via exogenous and endogenous sources. The typical clinical features of CS are related to hypercortisolism and include accumulation of central fat, moon facies, neuromuscular weakness, osteoporosis or bone fractures, metabolic complications, and mood changes. Traditionally, endogenous CS is classified as adrenocorticotropic hormone (ACTH)-dependent (about 80%) or ACTH- independent (about 20%). Among ACTH-dependent forms, pituitary corticotroph adenoma (Cushing's disease) is most common. Most pituitary tumors are sporadic, resulting from monoclonal expansion of a single mutated cell. Recently recurrent activating somatic driver mutations in the ubiquitin-specific protease 8 gene (USP8) were identified in almost half of corticotroph adenoma. Germline mutations in MEN1 (encoding menin), AIP (encoding aryl-hydrocarbon receptor-interacting protein), PRKAR1A (encoding cAMP-dependent protein kinase type I alpha regulatory subunit) and CDKN1B (encoding cyclin-dependent kinase inhibitor 1B; also known as p27 Kip1) have been identified in familial forms of pituitary adenomas. However, the frequency of familial pituitary adenomas is less than 5% in patients with pituitary adenomas. Among ACTH-independent CS, adrenal adenoma is most common. Rare adrenal causes of CS include primary bilateral macronodular adrenal hyperplasia (BMAH) or primary pigmented nodular adrenocortical disease (PPNAD).
Human papillomavirus (HPV) is a non-enveloped, double-stranded DNA virus. HPV infect mucoal and cutaneous epithelium resulting in several types of pathologies, most notably, cervical cancer. All types of HPV share a common genomic structure and encode eight proteins: E1, E2, E4, E5, E6, and E7 (early) and L1 and L2 (late). It has been demonstrated that E1 and E2 are involved in viral transcription and replication. The functions of the E4 protein is not yet fully understood. E5, E6, and E7 act as oncoproteins. E5 inhibits the V-ATPase, prolonging EGFR signaling and thereby promoting cell proliferation. The expression of E6 and E7 not only inhibits the tumor suppressors p53 and Rb, but also alters additional signalling pathways. Among these pathways, PI3K/Akt signalling cascade plays a very important role in HPV-induced carcinogenesis. The L1 and L2 proteins form icosahedral capsids for progeny virion generation.
MicroRNA (miRNA) is a cluster of small non-encoding RNA molecules of 21 - 23 nucleotides in length, which controls gene expression post-transcriptionally either via the degradation of target mRNAs or the inhibition of protein translation. Using high-throughput profiling, dysregulation of miRNAs has been widely observed in different stages of cancer. The upregulation (overexpression) of specific miRNAs could lead to the repression of tumor suppressor gene expression, and conversely the downregulation of specific miRNAs could result in an increase of oncogene expression; both these situations induce subsequent malignant effects on cell proliferation, differentiation, and apoptosis that lead to tumor growth and progress. The miRNA signatures of cancer observed in various studies differ significantly. These inconsistencies occur due to the differences in the study populations and methodologies used. This pathway map shows the summarized results from various studies in 9 cancers, each of which is presented in a review article.
Colorectal cancer (CRC) is the second largest cause of cancer-related deaths in Western countries. CRC arises from the colorectal epithelium as a result of the accumulation of genetic alterations in defined oncogenes and tumour suppressor genes (TSG). Two major mechanisms of genomic instability have been identified in sporadic CRC progression. The first, known as chromosomal instability (CIN), results from a series of genetic changes that involve the activation of oncogenes such as K-ras and inactivation of TSG such as p53, DCC/Smad4, and APC. The second, known as microsatellite instability (MSI), results from inactivation of the DNA mismatch repair genes MLH1 and/or MSH2 by hypermethylation of their promoter, and secondary mutation of genes with coding microsatellites, such as transforming growth factor receptor II (TGF-RII) and BAX. Hereditary syndromes have germline mutations in specific genes (mutation in the tumour suppressor gene APC on chromosome 5q in FAP, mutated DNA mismatch repair genes in HNPCC).
Endometrial cancer (EC) is the most common gynaecological malignancy and the fourth most common malignancy in women in the developed world after breast, colorectal and lung cancer. Two types of endometrial carcinoma are distinguished with respect to biology and clinical course. Type-I carcinoma is related to hyperestrogenism by association with endometrial hyperplasia, frequent expression of estrogen and progesterone receptors and younger age, whereas type-II carcinoma is unrelated to estrogen, associated with atrophic endometrium, frequent lack of estrogen and progesterone receptors and older age. The morphologic differences in these cancers are mirrored in their molecular genetic profile with type I showing defects in DNA-mismatch repair and mutations in PTEN, K-ras, and beta-catenin, and type II showing aneuploidy, p53 mutations, and her2/neu amplification.
Cancer of the skin is the most common cancer in Caucasians and basal cell carcinomas (BCC) account for 90% of all skin cancers. The vast majority of BCC cases are sporadic, though there is a rare familial syndrome basal cell nevus syndrome (BCNS, or Gorlin syndrome) that predisposes to development of BCC. In addition, there is strong epidemiological and genetic evidence that demonstrates UV exposure as a risk factor of prime importance. The development of basal cell carcinoma is associated with constitutive activation of sonic hedgehog signaling. The mutations in SMOH, PTCH1, and SHH in BCCs result in continuous activation of target genes. At a cellular level, sonic hedgehog signaling promotes cell proliferation. Mutations in TP53 are also found with high frequency (>50%) in sporadic BCC.
Breast cancer is the leading cause of cancer death among women worldwide. The vast majority of breast cancers are carcinomas that originate from cells lining the milk-forming ducts of the mammary gland. The molecular subtypes of breast cancer, which are based on the presence or absence of hormone receptors (estrogen and progesterone subtypes) and human epidermal growth factor receptor-2 (HER2), include: hormone receptor positive and HER2 negative (luminal A subtype), hormone receptor positive and HER2 positive (luminal B subtype), hormone receptor negative and HER2 positive (HER2 positive), and hormone receptor negative and HER2 negative (basal-like or triple-negative breast cancers (TNBCs)). Hormone receptor positive breast cancers are largely driven by the estrogen/ER pathway. In HER2 positive breast tumours, HER2 activates the PI3K/AKT and the RAS/RAF/MAPK pathways, and stimulate cell growth, survival and differentiation. In patients suffering from TNBC, the deregulation of various signalling pathways (Notch and Wnt/beta-catenin), EGFR protein have been confirmed. In the case of breast cancer only 8% of all cancers are hereditary, a phenomenon linked to genetic changes in BRCA1 or BRCA2. Somatic mutations in only three genes (TP53, PIK3CA and GATA3) occurred at >10% incidence across all breast cancers.
Hepatocellular carcinoma (HCC) is a major type of primary liver cancer and one of the rare human neoplasms etiologically linked to viral factors. It has been shown that, after HBV/HCV infection and alcohol or aflatoxin B1 exposure, genetic and epigenetic changes occur. The recurrent mutated genes were found to be highly enriched in multiple key driver signaling processes, including telomere maintenance, TP53, cell cycle regulation, the Wnt/beta-catenin pathway (CTNNB1 and AXIN1), the phosphatidylinositol-3 kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) pathway. Recent studies using whole-exome sequencing have revealed recurrent mutations in new driver genes involved in the chromatin remodelling (ARID1A and ARID2) and the oxidative stress (NFE2L2) pathways.
Gastric cancer (GC) is one of the world's most common cancers. According to Lauren's histological classification gastric cancer is divided into two distinct histological groups - the intestinal and diffuse types. Several genetic changes have been identified in intestinal-type GC. The intestinal metaplasia is characterized by mutations in p53 gene, reduced expression of retinoic acid receptor beta (RAR-beta) and hTERT expression. Gastric adenomas furthermore display mutations in the APC gene, reduced p27 expression and cyclin E amplification. In addition, amplification and overexpression of c-ErbB2, reduced TGF-beta receptor type I (TGFBRI) expression and complete loss of p27 expression are commonly observed in more advanced GC. The main molecular changes observed in diffuse-type GCs include loss of E-cadherin function by mutations in CDH1 and amplification of MET and FGFR2F.
Apoptotic cell death is achieved by the caspase-mediated\rcleavage of various vital proteins. Among caspase targets are proteins such as E-cadherin, Beta-catenin, alpha fodrin, GAS2, FADK, alpha adducin, HIP-55, and desmoglein involved in cell adhesion and maintenance of the cytoskeletal architecture. Cleavage of proteins such as APC and CIAP1 can further stimulate apoptosis by produce proapoptotic proteins (reviewed in Fischer et al., 2003. See also Wee et al., 2006 and the CASVM Caspase Substrates Database: http://www.casbase.org/casvm/squery/index.html )
The beta-catenin destruction complex plays a key role in the canonical Wnt signaling pathway. In the absence of Wnt signaling, this complex controls the levels of cytoplamic beta-catenin. Beta-catenin associates with and is phosphorylated by the destruction complex. Phosphorylated beta-catenin is recognized and ubiquitinated by the SCF-beta TrCP ubiquitin ligase complex and is subsequently degraded by the proteasome (reviewed in Kimelman and Xu, 2006)
Degradation of beta-catenin is initiated following amino-terminal serine/threonine phosphorylation. Phosphorylation of B-catenin at S45 by CK1 alpha primes the subsequent sequential GSK-3-mediated phosphorylation at Thr41, Ser37 and Ser33 (Amit et al., 2002 ; Lui et al., 2002)
The mechanisms involved in downregulation of TCF-dependent transcription are not yet very well understood. beta-catenin is known to recruit a number of transcriptional repressors, including Reptin, SMRT and NCoR, to the TCF/LEF complex, allowing the transition from activation to repression (Bauer et al, 2000; Weiske et al, 2007; Song and Gelmann, 2008). CTNNBIP1 (also known as ICAT) and Chibby are inhibitors of TCF-dependent signaling that function by binding directly to beta-catenin and preventing interactions with critical components of the transactivation machinery (Takemaru et al, 2003; Li et al, 2008; Tago et al, 2000; Graham et al, 2002; Daniels and Weiss, 2002). Chibby additionally promotes the nuclear export of beta-catenin in conjunction with 14-3-3/YWHAZ proteins (Takemura et al, 2003; Li et al, 2008). A couple of recent studies have also suggested a role for nuclear APC in the disassembly of the beta-catenin activation complex (Hamada and Bienz, 2004; Sierra et al, 2006). It is worth noting that while some of the players involved in the disassembly of the beta-catenin transactivating complex are beginning to be worked out in vitro, the significance of their role in vivo is not yet fully understood, and some can be knocked out with little effect on endogenous WNT signaling (see for instance Voronina et al, 2009)
Upon stimulation with WNT ligand, AXIN and GSK3beta are recruited to the plasma membrane through interaction with DVL (Tamai et al, 2004; Mao et al, 2001; reviewed in He et al, 2004). Polymerization of membrane-associated DVL and GSK3beta- and CSNK1-mediated phosphorylation of LRP5/6 establish a feed-forward mechanism for enhanced membrane recruitment of AXIN upon WNT signaling (Tamai et al, 2004; Cong et al, 2004; Zeng et al, 2005; Bilic et al, 2007). In Xenopus oocytes, but not necessarily all sytems, AXIN is present in limiting concentrations and is considered rate limiting for the assembly of the destruction complex (Lee et al, 2003; Benchabane et al, 2008; Tan et al, 2012; reviewed in MacDonald et al, 2009). The recruitment of AXIN away from the destruction complex upon WNT stimulation effectively destabilizes the destruction complex and contributes to the accumulation of free beta-catenin (Kikuchi, 1999; Lee et al, 2003). AXIN association with the destruction complex is also regulated by phosphorylation. In the active destruction complex, AXIN is phosphorylated by GSK3beta; dephosphorylation by protein phosphatase 1 (PP1) or protein phosphatase 2A (PP2A) destabilizes the interaction of AXIN with the other components of the destruction complex and promotes its disassembly (Luo et al, 2007; Willert et al, 1999; Jho et al, 1999). Free AXIN is also subject to degradation by the 26S proteasome in a manner that depends on the poly-ADP-ribosylating enzymes tankyrase 1 and 2 (Huang et al, 2009)
GSK3beta is subject to in-frame missplicing in CML stem cells resulting in the production of mutant protein that lacks the AXIN and FRAT binding domains. Cells containing this mutant GSK3beta show elevated levels of nuclear beta-catenin and enhanced TCF-dependent reporter activity (Jamieson et al, 2008; Abrahamsson et al, 2009)
S33 mutations of beta-catenin interfere with GSK3 phosphorylation and result in stabilization and nuclear localization of the protein and enhanced WNT signaling (Groen et al, 2008; Nhieu et al, 1999; Clements et al, 2002; reviewed in Polakis, 2000). S33 mutations have been identified in cancers of the central nervous system, liver, endometrium and stomach, among others (reviewed in Polakis, 2000)
S37 mutations of beta-catenin interfere with GSK3 phosphorylation and stabilize the protein, resulting in enhanced WNT pathway signaling (Nhieu et al, 1999; Clements et al, 2002; reviewed in Polakis, 2000). S37 mutations have been identified in cancers of the brain, liver, ovary and large intestine, among others (reviewed in Polakis, 2000)
S45 mutants of beta-catenin have been identified in colorectal and hepatocellular carcinomas, soft tissue cancer and Wilms Tumors, among others (reviewed in Polakis, 2000). These mutations abolish the CK1alpha phosphorylation site of beta-catenin which acts as a critical priming site for GSK3 phosphorylation of T41( and subsequently S37 and S33) thus preventing its ubiquitin-mediated degradation (Morin et al, 1997; Amit et al, 2002)
T41 mutations of beta-catenin interfere with GSK3 phosphorylation and result in stabilization and nuclear accumulation of the protein (Moreno-Bueno et al, 2002; Taniguchi et al, 2002; reviewed in Polakis, 2012). T41 mutations have been identified in cancers of the liver and brain, as well as in the pituitary, endometrium, large intestine and skin, among others (reviewed in Polakis, 2000; Saito-Diaz et al, 2013)
APC has been shown to be reversibly modified with K63-linked polyubiquitin chains. This modification is required for the association is required for the assembly of the destruction complex and subsequent degradation of beta-catenin in the absence of WNT ligand. K63-polyubiquitination of APC is lacking in a number of colorectal cancer cell lines expressing truncated forms of APC, and these lines have aberrantly high beta-catenin levels and WNT pathway activation (Tran and Polakis, 2012)
Mutations in the APC tumor suppressor gene are common in colorectal and other cancers and cluster in the central mutation cluster region (MCR) of the gene (Miyoshi et al, 1992; Nagase and Nakamura, 1993; Dihlmann et al, 1999; reviewed in Bienz and Clevers, 2000). These mutations generally result in truncated proteins that destabilize the destruction complex and result in elevated WNT pathway activation (reviewed in Polakis, 2000)
Alterations in AXIN1 have been detected in a number of different cancers including liver and colorectal cancer and medullablastoma, among others (reviewed in Salahshor and Woodgett, 2005). Missense and nonsense mutations that disrupt or remove protein-protein interaction domains are common, and AXIN variants in cancers tend to disrupt the formation of a functional destruction complex (Satoh et al, 2000; Taniguchi et al, 2002; Webster et al, 2000; Shimizu et al, 2002)
AMER1/WTX is a known component of the destruction complex and interacts directly with beta-catenin through the C-terminal half (Major et al, 2007). siRNA depletion of AMER1 in mammalian cells stabilizes cellular beta-catenin levels and increases the expression of a beta-catenin-dependent reporter gene, suggesting that AMER1 is a tumor suppressor gene (Major et al, 2007; reviewed in Huff, 2011). Consistent with this, nonsense and missense mutations that truncate AMER1 and result in loss of the beta-catenin binding region have been identified in Wilms tumor, a pediatric kidney cancer (Ruteshouser et al, 2008; Wegert et al, 2009)
Humans have 16 Overian tumour domain (OTU) family DUBs that can be evolutionally divided into three classes, the OTUs, the Otubains (OTUBs), and the A20-like OTUs (Komander et al. 2009). OTU family DUBs can be highly selective in the type of ubiquitin crosslinks they cleave. OTUB1 is specific for K48-linked chains, whereas OTUB2 can cleave K11, K63 and K48-linked poly-Ub (Wang et al. 2009, Edelmann et al. 2009, Mevissen et al. 2013). A20 prefers K48-linked chains, Cezanne is specific for K11-linked chains, and TRABID acts on both K29, K33 and K63-linked poly-Ub (Licchesi et al. 2011, Komander & Barford 2008, Bremm et al. 2010, Mevissen et al. 2013). The active site of the OTU domain contains an unusual loop not seen in other thiol-DUBs and can lack an obvious catalytic Asp/Asn (Komander & Barford 2009, Messick et al. 2008, Lin et al. 2008). A20 and OTUB1 have an unusual mode of activity, binding directly to E2 enzymes (Nakada et al. 2010, Wertz et al. 2004)