Inactivating PAPSS2 mutations in a patient with premature pubarche.

Dehydroepiandrosterone (DHEA) sulfotransferase, known as SULT2A1, converts the androgen precursor DHEA to its inactive sulfate ester, DHEAS [corrected], thereby preventing the conversion of DHEA to an active androgen. SULT2A1 requires 3'-phosphoadenosine-5'-phosphosulfate (PAPS) for catalytic activity. We have identified compound heterozygous mutations in the gene encoding human PAPS synthase 2 (PAPSS2) in a girl with premature pubarche, hyperandrogenic anovulation, very low DHEAS levels, and increased androgen levels. In vitro coincubation of human SULT2A1 and wild-type or mutant PAPSS2 proteins confirmed the inactivating nature of the mutations. These observations indicate that PAPSS2 deficiency is a monogenic adrenocortical cause of androgen excess.

Degenerative knee joint disease in mice lacking 3'-phosphoadenosine 5'-phosphosulfate synthetase 2 (Papss2) activity: a putative model of human PAPSS2 deficiency-associated arthrosis.

OBJECTIVE: Murine brachymorphism (bm) results from an autosomal recessive mutation of the Papss2 gene that encodes 3'-phosphoadenosine 5'-phosphosulfate synthetase 2, one of the principal enzymes required for the sulfation of extracellular matrix molecules in cartilage and other tissues. A spondyloepimetaphyseal dysplasia has been identified in Pakistani kindred having a mutation of PAPSS2. In addition to skeletal malformations that include short stature evident at birth due to limb shortening, brachydactyly, and kyphoscoliosis, affected individuals demonstrate premature onset degenerative joint disease. We investigated whether loss of Papss2 activity would similarly lead to degenerative joint disease in mice. METHODS: Mice carrying the bm mutation on a C57BL/6 background were obtained from the Jackson Laboratory. Limbs were analyzed by micro-computed tomography (microCT) and histology. RESULTS: At 12 months of age both male and female bm mice exhibited severe degenerative knee joint disease, with cartilage damage being primarily evident in the patello-femoral and medial compartments. Control 12-14-month-old C57BL/6 mice, in contrast, only occasionally demonstrated minimal cartilage damage. muCT imaging of bm limbs revealed shortened diaphyses associated with flared metaphyses in the proximal elements of both fore and hind limbs. Additionally, the bm hind limbs demonstrated extensive structural alterations, characterized by distortion of the patello-femoral groove, and prominent bowing of both tibia and fibula. CONCLUSIONS: The bm mutant, which develops severe articular cartilage lesions of the knee joint by approximately 12 months of age, represents a novel example of murine degenerative joint disease, possibly representing a model of human PAPSS2 deficiency-associated arthrosis.

Nuclear localization of PAPS synthetase 1: a sulfate activation pathway in the nucleus of eukaryotic cells.

Sulfation is a major modification of many molecules in eukaryotes that is dependent on the enzymatic synthesis of an activated sulfate donor, 3'-phosphoadenosine 5'-phosphosulfate (PAPS). While sulfate activation has long been assumed to occur in the cytosol, we show in this study that human PAPS synthetase 1 (PAPSS1), a bifunctional ATP sulfurylase/adenosine 5'-phosphosulfate (APS) kinase enzyme sufficient for PAPS synthesis, accumulates in the nucleus of mammalian cells. Nuclear targeting of the enzyme is mediated by its APS kinase domain and requires a catalytically dispensable 21 amino acid sequence at the amino terminus. Human PAPSS1 and Drosophila melanogaster PAPSS localize to the nucleus in yeast and relieve the methionine auxotrophy of ATP sulfurylase- or APS kinase-deficient strains, suggesting that PAPSS1 is fully functional in vivo when targeted to the nucleus. A second PAPS synthetase gene, designated PAPSS2, has recently been described, mutations of which are responsible for abnormal skeletal development in human spondyloepimetaphyseal dysplasia and murine brachymorphism. We found that PAPSS2, which localizes to the cytoplasm when ectopically expressed in mammalian cells, is relocated to the nucleus when coexpressed with PAPSS1. Taken together, these results indicate that a sulfation pathway might exist in the nucleus of eukaryotic cells. -Besset, S., Vincourt, J.-B., Amalric, F., Girard, J.-P. Nuclear localization of PAPS synthetase 1: a sulfate activation pathway in the nucleus of eukaryotic cells.