Disease relevance of DIM1

• The yeast 18S rRNA dimethylase gene DIM1 was cloned previously by complementation in Escherichia coli and shown to be essential for viability in yeast [1].

High impact information on DIM1

• To test whether the processing defect is a consequence of the absence of the dimethylated nucleotides or of the Dim1p dimethylase itself, a cis-acting mutation was created in which both dimethylated adenosines are replaced by guanosine residues [1].
• Notably, some of these components are part of both early 90S and intermediate 40S pre-particles in the nucleolus (e.g. Enp1p, Dim1p and Rrp12p), whereas others (e.g. Rio2p and Nob1p) are found mainly on late cytoplasmic pre-40S subunits [2].
• Interestingly, the Schizosaccharomyces pombe orthologue of Dib1p, Dim1p, was previously assigned a role in cell cycle progression [3].
• In addition, double mutants with either dim1-delta or dim2-1 and the endocytosis mutants end4-1 or act1-1 displayed synthetic growth defects, indicating that the DIM gene products function in a common or parallel endocytic pathway [4].
• The processing steps inhibited were nucleolar, and consistent with this, Dim1p was shown to localize mostly to this cellular compartment. dim1-2 was isolated from a library of conditionally lethal alleles of DIM1 [5].

Biological context of DIM1

• Regarding base methylations, the gene DIM1, responsible for modification of the conserved dimethyladenosines near the 3' end of 18S rRNA, has been shown to be essential for viability in S. cerevisiae and is suggested to play a role in the nucleocytoplasmic transport of the small ribosomal subunit [6].
• Using random mutagenesis of the motor region of MYO5, we identified four independent dominant point mutations that suppress the temperature-sensitive growth phenotype of the she4/dim1 null mutant [7].
• Finally, we provide evidence that Dim1p also participates in the nuclear export of lid1(+) mRNA and that it is likely the combined loss of both of these two Dim1p functions which compromises Lid1p levels in the absence of proper Dim1p function [8].
• This protein has 38% amino acid sequence identity with and is evolutionally related to yeast Dim1 protein [9].

Anatomical context of DIM1

• Yeast 18S rRNA dimethylase Dim1p: a quality control mechanism in ribosome synthesis [5]?

Associations of DIM1 with chemical compounds

• Like ksgA, DIM1 belongs to the erm family of prokaryotic 23 S rRNA dimethylases responsible for erythromycin resistance [10].

Physical interactions of DIM1

• Two-hybrid and biochemical experiments showed that She4p/Dim1p interacts with the motor domain of Myo3/5p through its UCS domain [7].

Other interactions of DIM1

• Our results suggest that She4p/Dim1p is required for structural integrity or regulation of the motor domain of unconventional myosins [7].
• She4p/Dim1p was required for Myo5p localization to cortical patch-like structures [7].

References