Disease relevance of PSD2

• The PSD2 gene was heterologously expressed by infection of Sf-9 insect cells with recombinant baculovirus, resulting in a 10-fold increase in PSD activity [1].

High impact information on PSD2

• Deletion of the mitochondrial PE pathway gene PSD1 was synthetically lethal with the crd1delta mutant, whereas deletion of the Golgi and endoplasmic reticulum pathway genes PSD2 and DPL1 did not result in synthetic lethality [2].
• These data indicate that the gene isolated is the structural gene for PSD2 and that the PSD1 and PSD2 enzymes account for all yeast PSD activity [1].
• The null allele of PSD2 was introduced into yeast strains by one-step gene deletion/disruption with a HIS3 marker gene [1].
• Physical mapping experiments demonstrate that the PSD2 is located on chromosome 7 [1].
• This nutritional requirement was utilized to isolate the gene encoding the PSD2 enzyme by complementation [1].

Biological context of PSD2

• The PSD2 amino acid sequence also shows significant homology to the C2 regions of protein kinase C and synaptotagmin [1].

Anatomical context of PSD2

• Unlike the PSD1 activity, the PSD2 enzyme activity does not localize to the mitochondria, but to a low density subcellular compartment with fractionation properties similar to both vacuoles and Golgi [3].
• Two types of decarboxylases are found in yeast, PSD1 and PSD2, that localize to the inner mitochondrial membrane and the Golgi/vacuole membrane, respectively [4].

Associations of PSD2 with chemical compounds

• The second PS decarboxylase gene (PSD2) is not regulated on a transcriptional level by inositol and/or ethanolamine [5].
• A triple yeast mutant was constructed which lacks BST1, the gene for sphingosine lyase, besides the phosphatidylserine decarboxylases PSD1 and PSD2 [6].
• Strains containing both the psd1-delta 1::TRP1 and psd2-delta 1::HIS3 null alleles, however, express no detectable PSD activity, are ethanolamine auxotrophs and show a severe deficit in the conversion of [3H]serine-labeled phosphatidylserine to phosphatidylethanolamine [1].
• The present studies demonstrate the presence of a second enzyme activity (denoted PSD2), which, depending on the method of evaluation, accounts for 4-12% of the total cellular phosphatidylserine decarboxylase activity found in wild type [3].
• On further purification by reverse-phase high performance liquid chromatography, two small cysteine-rich polypeptides were obtained (Psd1 and Psd2) [7].

Other interactions of PSD2

• Disruption of the second PS decarboxylase gene (PSD2) does not affect the INO1 regulation [5].

References