Friday 19 October 2007
Mitochondrial RNA-processing endoribonuclease (RNase MRP) cleaves mitochondrial RNA complementary to the light chain of the displacement loop at a unique site.
The enzyme is a ribonucleoprotein whose RNA component RMRP is a nuclear gene product.
The RMRP gene encodes the untranslated RNA component of the mitochondrial RNA-processing ribonuclease, RNase MRP. The RNA component RMRP is the first RNA encoded by a single-copy gene in the nucleus and imported into mitochondria. The RNRP gene is untranslated, i.e., it encodes an RNA not a protein.
germline mutations in RMRP
- cartilage-hair hypoplasia (MIM.250250)
- metaphyseal dysplasia without hypotrichosis (MIM.250460)
- anauxetic dysplasia (MIM.607095)
In vitro testing of RNase MRP multiprotein-specific mRNA and rRNA cleavage of different mutations revealed a strong correlation between the decrease in rRNA cleavage in ribosomal assembly and the degree of bone dysplasia, whereas reduced mRNA cleavage, and thus cell-cycle impairment, predicts the presence of hair hypoplasia, immunodeficiency, and hematological abnormalities and thus increased cancer risk. (#17701897#)
Thiel CT, Mortier G, Kaitila I, Reis A, Rauch A. Type and level of RMRP functional impairment predicts phenotype in the cartilage hair hypoplasia-anauxetic dysplasia spectrum. Am J Hum Genet. 2007 Sep;81(3):519-29. PMID: #17701897#