Disease relevance of MIR1

• The MIR1 and YER053C proteins were expressed in Escherichia coli and then reconstituted into liposomes [1].
• One protein that interacted strongly with capsid was p32, a cellular protein which is known to interact with other viral proteins [2].
• Our results are consistent with the possibility that the interaction of p32 with capsid plays a role in the regulation of nucleocapsid assembly and/or virus-host interactions [2].
• Rubella virus capsid associates with host cell protein p32 and localizes to mitochondria [2].

High impact information on MIR1

• Haploid cells carrying a disrupted MIR1 allele were unable to grow on a non-fermentable carbon source but grew in media containing glucose, indicating that the MIR1 protein is essential for mitochondrial function [3].
• Immunoelectron microscopy and subfractionation of mitochondria indicate that p32 is located in contact sites between the outer and inner mitochondrial membranes [4].
• The deduced amino-acid sequence of p32 shows roughly 40% identity with proteins of bovine heart and rat liver that have been suggested to be mitochondrial phosphate carriers [3].
• The cell cycle of Fucus zygotes presented the other main features of a somatic cell cycle, such as a functional spindle assembly checkpoint that targets CDKs and the regulation of the early synthesis of two PSTAIRE CDKs, p32 and p34, and the associated histone H1 kinase activity as well as the regulation of CDKs by tyrosine phosphorylation [5].
• Mitochondrial phosphate-carrier deficiency: a novel disorder of oxidative phosphorylation [6].

Biological context of MIR1

• The predicted amino acid sequence of the YER053C protein is much more similar to that of mitochondrial phosphate transporters of other species than that of MIR1 [1].
• Our data suggest that p32 contains a binding site specific for the signal sequence region of mitochondrial preproteins [7].
• Here we have purified p32 after expression of its gene in Escherichia coli and assayed its ability to bind to various preproteins containing signal sequences for protein translocation into mitochondria, chloroplasts, or the endoplasmic reticulum [7].
• Yeast mitochondria lacking the phosphate carrier/p32 are blocked in phosphate transport but can import preproteins after regeneration of a membrane potential [8].
• We analyzed the submitochondrial location and biogenesis pathway of the phosphate carrier (PiC), also termed p32, of Saccharomyces cerevisiae mitochondria, PiC/p32 was found to behave as an integral membrane protein that cofractionated with the ADP/ATP carrier of the inner membrane [9].

Anatomical context of MIR1

• Fab fragments derived from both anti-idiotypic antibodies and monospecific antibodies against purified p32 inhibited protein import into mitochondria [4].
• In contrast, mRNAs encoding Cox6p, Cox5a, Aac1p, and Mir1p are found enriched in free cytoplasmic polysome fractions [10].
• Phosphate transport in yeast vacuoles [11].
• Yeast mitochondrial phosphate transport activity has been reconstituted from the import receptor (MIR) expressed as inclusion bodies in Escherichia coli [12].

Associations of MIR1 with chemical compounds

• YER053C also did not support the growth of the MIR1 null mutant on glycerol [1].
• We have purified peptides matching the highly conserved motif Pro-X-(Asp/glu)-X-X-(Lys/Arg)-X-(Arg/lys) (X is an unspecified amino acid) of the triplicate gene structure sequence of the beef heart PTP [13].
• The PTP from S. cerevisiae migrates as a single band (35 kDa) in sodium dodecyl sulfate gels with the same mobility as the N-ethylmaleimide-alkylated beef heart PTP [13].
• PTP was solubilized with N-lauroylsarcosinate and Triton X-100 and purified with a yield of about 2 mg/L of induced bacterial culture [12].
• Phosphate transport in yeast mitochondria: is the phosphate carrier a part of the oligomycin-sensitive adenosine triphosphatase complex [14]?

Other interactions of MIR1

• We propose that Pic2p is a minor form of mPic which plays a role under specific stress conditions [15].

References