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