High impact information on IPT1

• Strains with a nonfunctional IPT1 allele lacked mannose-(inositol-phosphate)(2)-ceramide in their plasma membranes, bound significantly less DmAMP1 compared with wild-type strains, and were highly resistant to DmAMP1-mediated membrane permeabilization [1].
• Transcription of the IPT1 gene is responsive to changes in activity of Pdr1p and Pdr3p [2].
• A screen conducted to find the yeast genes necessary for its fungicidal action identified two novel syringomycin E response genes, SYR3 and SYR4 [3].
• SYR4 was identified by Tn5 inactivation of genomic library plasmids that complemented a syr4 mutant allele [3].
• These results show that SKN1, together with IPT1, is involved in sphingolipid biosynthesis in S. cerevisiae [4].

Biological context of IPT1

• Loss of IPT1 has complex effects on drug resistance of the resulting strain, consistent with an important role for mannosyldiinositol phosphorylceramide in normal plasma membrane function [2].
• Consistent with altered cell surface properties, kti6 cells resist hygromycin B, syringomycin E, and nystatin, antibiotics that require intact membrane potentials or provoke membrane disruption [5].

Anatomical context of IPT1

• KTI6 is allelic to IPT1, coding for mannosyl-diinositolphospho-ceramide [M(IP)(2)C] synthase, which produces M(IP)(2)C, the major plasma membrane sphingolipid. kti6 membranes lack M(IP)(2)C and sphingolipid mutants that have reduced levels of M(IP)(2)C precursors, including the sphingolipid building block ceramide survive zymocin [5].

Associations of IPT1 with chemical compounds

• Furthermore, the genes CSG2 and IPT1 were found to be required for normal growth of gas1Delta cells in the presence of 1 M sorbitol [6].
• The last step in formation of the major sphingolipid in the yeast plasma membrane, mannosyldiinositol phosphorylceramide, is catalyzed by the product of the IPT1 gene, inositol phosphotransferase (Ipt1p) [2].

Other interactions of IPT1

• Genetic analysis indicates that Kti6 is likely to act upstream of lipid raft proton pump Kti10/Pma1, a previously identified zymocin sensitivity factor [5].

References