3.1.3.56	evolution	enzyme Siw14 is a member of the protein tyrosine-phosphatase (PTP) superfamily. Siw14 has a cysteine-based, class I CX5R(S/T) motif that defines the family of protein-tyrosine phosphatases (PTPs). Bioinformatic studies lead to Siw14 being classified as belonging within a specialist subgroup of PTPs, the dual specific protein-tyrosine phosphatases (DUSPs). The DUSPs themselves include a distinct class of proteins that appears not to have substantial activity against phosphoproteins. These are usually described as nonprotein-specific or atypical phosphatases. The inclusion of Siw14 in this category is supported by biochemical analysis, the enzyme's catalytic activity against 5-diphosphoinositol 1,2,3,4,6-pentakisphosphate (5-InsP7) is several orders of magnitude greater than that against 4-nitrophenyl phosphate, a generic protein phosphatase substrate. Other members of this atypical DUSP subgroup preferentially hydrolyze either phosphorylated carbohydrates, inositol lipids, or triphosphate groups in mRNA. Thus, this DUSP subfamily exhibits catalytic site diversity that is not observed for classical PTPs	-, 751120	
3.1.3.56	evolution	phylogenetic analyses are performed to delineate the evolutionary history of the polyphosphate 5-phosphatase family in major angiosperm lineages	771726	
3.1.3.56	malfunction	mutations in INPP5K have been detected in patients with a rare form of autosomal recessive congenital muscular dystrophy with cataract, short stature and intellectual disability	768412	
3.1.3.56	malfunction	the increase in the levels of 1D-myo-inositol 1,4,5-trisphosphate/Ca2+ caused by deficiency of inositol polyphosphate 5-phosphatases is sufficient to break pollen dormancy and to trigger early germination	729621	
3.1.3.56	malfunction	transgenic tobacco plants overexpressing Le5PT1 exhibit reduced growth in height, leaf area, and dry weight compared to wild type plants. The transgenic plants have lower water use efficiency than wild type and the downregulation of the drought-responsive gene, NtERD10B	-, 768111	
3.1.3.56	metabolism	inositol pyrophosphate metabolism in Saccharomyces cerevisiae involving enzyme Siw14, overview	-, 751120	
3.1.3.56	additional information	active site architecture and substrate binding pocket structure, overview. The core catalytic domain of Siw14 is formed by residues 116-281. The three structural elements that demarcate a 9.2-A-deep substrate-binding pocket each have spatial equivalents in PTPs, but these are specialized for Siw14 to bind and hydrolyze the intensely negatively charged diphosphoinositol phosphates. A loop between the alpha5 and alpha6 helices, corresponding to the Q-loop in PTPs, contains a lysine and an arginine that extend into the catalytic pocket due to displacement of the alpha5 helix orientation through intramolecular crowding caused by three bulky, hydrophobic residues. The general-acid loop in PTPs is replaced in Siw14 with a flexible loop that does not use an aspartate or glutamate as a general acid	-, 751120	
3.1.3.56	physiological function	alters abscisic acid and light signaling, stomatal opening, seedling development	772168	
3.1.3.56	physiological function	alters abscisic acid signaling, seedling development	772168	
3.1.3.56	physiological function	cotyledon vein development, alters auxin, abscisic acid, sugar and PHOTOTROPIN1 signaling, root gravitropism, vesicle trafficking	772168	
3.1.3.56	physiological function	divergent functions of polyphosphate 5-phosphatase genes, allowing the angiosperms to successfully adapt to a great number of ecological niches	771726	
3.1.3.56	physiological function	downregulation of INPP5K disrupts muscle fiber morphology and results in abnormal eye development	749530	
3.1.3.56	physiological function	Gs5PTase8 plays a positive role in salt tolerance and might be a candidate gene for improving soybean adaptation to salt stress. Ectopic expression of Gs5PTase8 enhances salt tolerance in plants	772178	
3.1.3.56	physiological function	INPP5K functions extend from control of insulin signaling, endoplasmic reticulum stress response and structural integrity, myoblast differentiation, cytoskeleton organization, cell adhesion and migration, renal osmoregulation, to cancer	768412	
3.1.3.56	physiological function	mutations of the isoform SHIP2 result in defects in insulin signaling and obesity	730981	
3.1.3.56	physiological function	pollen dormancy and germination	772168	
3.1.3.56	physiological function	SHIP2 plays a role in negative regulation of insulin signaling and as a potential drug target for obesity and type 2 diabetes	730984	
3.1.3.56	physiological function	the enzyme has essential functions in growth, development, and stress responses in plants, yeasts, and animals	771726	
3.1.3.56	physiological function	the enzyme is crucial for maintaining pollen dormancy	729621	
3.1.3.56	physiological function	the enzyme is involved in plant growth and abiotic stress responses. Le5PT1 may have a negative role in response to water deficit through the repression of drought-inducible genes that in turn affects plant growth and development	-, 768111	
3.1.3.56	physiological function	the enzyme links endoplasmic reticulum stress to insulin resistance in skeletal muscle	751561