TY  - INPR
A1  - Brenner, Marian
A1  - Zink, Christoph
A1  - Witzinger, Linda
A1  - Keller, Angelika
A1  - Hadamek, Kerstin
A1  - Bothe, Sebastian
A1  - Neuenschwander, Martin
A1  - Villmann, Carmen
A1  - von Kries, Jens Peter
A1  - Schindelin, Hermann
A1  - Jeanclos, Elisabeth
A1  - Gohla, Antje
T1  - 7,8-Dihydroxyflavone is a direct inhibitor of pyridoxal phosphatase
T2  - eLife
N2  - Vitamin B6 deficiency has been linked to cognitive impairment in human brain disorders for decades. Still, the molecular mechanisms linking vitamin B6 to these pathologies remain poorly understood, and whether vitamin B6 supplementation improves cognition is unclear as well. Pyridoxal phosphatase (PDXP), an enzyme that controls levels of pyridoxal 5’-phosphate (PLP), the co-enzymatically active form of vitamin B6, may represent an alternative therapeutic entry point into vitamin B6-associated pathologies. However, pharmacological PDXP inhibitors to test this concept are lacking. We now identify a PDXP and age-dependent decline of PLP levels in the murine hippocampus that provides a rationale for the development of PDXP inhibitors. Using a combination of small molecule screening, protein crystallography and biolayer interferometry, we discover and analyze 7,8-dihydroxyflavone (7,8-DHF) as a direct and potent PDXP inhibitor. 7,8-DHF binds and reversibly inhibits PDXP with low micromolar affinity and sub-micromolar potency. In mouse hippocampal neurons, 7,8-DHF increases PLP in a PDXP-dependent manner. These findings validate PDXP as a druggable target. Of note, 7,8-DHF is a well-studied molecule in brain disorder models, although its mechanism of action is actively debated. Our discovery of 7,8-DHF as a PDXP inhibitor offers novel mechanistic insights into the controversy surrounding 7,8-DHF-mediated effects in the brain.
KW  - 7,8-dihydroxyflavone (7,8-DHF)
KW  - pyridoxal phosphatase (PDXP)
KW  - vitamin B6
KW  - PDXP inhibitors
Y1  - 2024
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-350446
ER  - 
TY  - JOUR
A1  - Jeanclos, Elisabeth
A1  - Knobloch, Gunnar
A1  - Hoffmann, Axel
A1  - Fedorchenko, Oleg
A1  - Odersky, Andrea
A1  - Lamprecht, Anna‐Karina
A1  - Schindelin, Hermann
A1  - Gohla, Antje
T1  - Ca\(^{2+}\) functions as a molecular switch that controls the mutually exclusive complex formation of pyridoxal phosphatase with CIB1 or calmodulin
JF  - FEBS Letters
N2  - Pyridoxal 5′‐phosphate (PLP) is an essential cofactor for neurotransmitter metabolism. Pyridoxal phosphatase (PDXP) deficiency in mice increases PLP and γ‐aminobutyric acid levels in the brain, yet how PDXP is regulated is unclear. Here, we identify the Ca\(^{2+}\)‐ and integrin‐binding protein 1 (CIB1) as a PDXP interactor by yeast two‐hybrid screening and find a calmodulin (CaM)‐binding motif that overlaps with the PDXP‐CIB1 interaction site. Pulldown and crosslinking assays with purified proteins demonstrate that PDXP directly binds to CIB1 or CaM. CIB1 or CaM does not alter PDXP phosphatase activity. However, elevated Ca\(^{2+}\) concentrations promote CaM binding and, thereby, diminish CIB1 binding to PDXP, as both interactors bind in a mutually exclusive way. Hence, the PDXP‐CIB1 complex may functionally differ from the PDXP‐Ca\(^{2+}\)‐CaM complex.
KW  - calmodulin
KW  - chronophin
KW  - CIB1
KW  - haloacid dehalogenase
KW  - pyridoxal phosphatase
KW  - vitamin B6
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-217963
VL  - 594
IS  - 13
SP  - 2099
EP  - 2115
ER  - 
TY  - JOUR
A1  - Gohla, Antje
T1  - Do metabolic HAD phosphatases moonlight as protein phosphatases?
JF  - BBA - Molecular Cell Research
N2  - Mammalian haloacid dehalogenase (HAD)-type phosphatases have evolved to dephosphorylate a wide range of small metabolites, but can also target macromolecules such as serine/threonine, tyrosine-, and histidine-phosphorylated proteins. To accomplish these tasks, HAD phosphatases are equipped with cap domains that control access to the active site and provide substrate specificity determinants. A number of capped HAD phosphatases impact protein phosphorylation, although structural data are consistent with small metabolite substrates rather than protein substrates. This review discusses the structures, functions and disease implications of the three closely related, capped HAD phosphatases pyridoxal phosphatase (PDXP or chronophin), phosphoglycolate phosphatase (PGP, also termed AUM or glycerol phosphatase) and phospholysine phosphohistidine inorganic pyrophosphate phosphatase (LHPP or HDHD2B). Evidence in support of small metabolite and protein phosphatase activity is discussed in the context of the diversity of their biological functions.
KW  - actin cytoskeleton
KW  - cancer
KW  - haloacid dehalogenase-type phosphatase
KW  - major depression
KW  - metabolism
KW  - vitamin B6
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-233168
VL  - 1866
ER  - 
TY  - JOUR
A1  - Jeanclos, Elisabeth
A1  - Albersen, Monique
A1  - Ramos, Rúben J. J.
A1  - Raab, Annette
A1  - Wilhelm, Christian
A1  - Hommers, Leif
A1  - Lesch, Klaus-Peter
A1  - Verhoeven-Duif, Nanda M.
A1  - Gohla, Antje
T1  - Improved cognition, mild anxiety-like behavior and decreased motor performance in pyridoxal phosphatase-deficient mice
JF  - BBA - Molecular Basis of Disease
N2  - Pyridoxal 5′-phosphate (PLP) is an essential cofactor in the catalysis of ~140 different enzymatic reactions. A pharmacological elevation of cellular PLP concentrations is of interest in neuropsychiatric diseases, but whole-body consequences of higher intracellular PLP levels are unknown. To address this question, we have generated mice allowing a conditional ablation of the PLP phosphatase PDXP. Ubiquitous PDXP deletion increased PLP levels in brain, skeletal muscle and red blood cells up to 3-fold compared to control mice, demonstrating that PDXP acts as a major regulator of cellular PLP concentrations in vivo. Neurotransmitter analysis revealed that the concentrations of dopamine, serotonin, epinephrine and glutamate were unchanged in the brains of PDXP knockout mice. However, the levels of γ-aminobutyric acid (GABA) increased by ~20%, demonstrating that elevated PLP levels can drive additional GABA production. Behavioral phenotyping of PDXP knockout mice revealed improved spatial learning and memory, and a mild anxiety-like behavior. Consistent with elevated GABA levels in the brain, PDXP loss in neural cells decreased performance in motor tests, whereas PDXP-deficiency in skeletal muscle increased grip strength. Our findings suggest that PDXP is involved in the fine-tuning of GABA biosynthesis. Pharmacological inhibition of PDXP might correct the excitatory/inhibitory imbalance in some neuropsychiatric diseases.
KW  - pyridoxal phosphatase
KW  - vitamin B6
KW  - γ-Aminobutyric acid (GABA)
KW  - motor performance
KW  - neuropsychiatric diseases
KW  - neurotransmitter biosynthesis
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-323396
VL  - 1865
ER  -