Involvement of histidine permease (Hip1p) in manganese transport in Saccharomyces cerevisiae

In a search for components involved in Mn2+ homeostasis in the budding yeast Saccharomyces cerevisiae, we isolated a mutant with modifications in Mn2+ transport. The mutation was found to be located in HIP1, a gene known to encode a high-affinity permease for histidine. The mutation, designated hip1-272, caused a frameshift that resulted in a stop codon at position 816 of the 1812-bp ORF. This mutation led to Mn2+ resistance, whereas the corresponding null mutation did not. Both hip1-272 cells and the null mutant exhibited low tolerance to divalent cations such as Co2+, Ni2+, Zn2+, and Cu2+. The Mn2+ phenotype was not influenced by supplementary histidine in either mutant, whereas the sensitivity to other divalent cations was alleviated by the addition of histidine. The cellular Mn2+ content of the hip1-272 mutant was lower than that of wild type of null mutant, due to increase rates of Mn2+ efflux. We propose that Hip1p is involved in Mn2+ transport, carrying out a function related to Mn2+ export.