Mitochondrial ribosomal protein L42 explained

28S ribosomal protein L42, mitochondrial is a protein that in humans is encoded by the MRPL42 gene.^{[1] [2] [3]}

Mammalian mitochondrial ribosomal proteins are encoded by nuclear genes and help in protein synthesis within the mitochondrion. Mitochondrial ribosomes (mitoribosomes) consist of a small 28S subunit and a large 39S subunit. They have an estimated 75% protein to rRNA composition compared to prokaryotic ribosomes, where this ratio is reversed. Another difference between mammalian mitoribosomes and prokaryotic ribosomes is that the latter contain a 5S rRNA. Among different species, the proteins comprising the mitoribosome differ greatly in sequence, and sometimes in biochemical properties, which prevents easy recognition by sequence homology. This gene encodes a protein identified as belonging to both the 28S and the 39S subunits. Further experiments will be needed to identify the specific subunit localization. Sequence analysis identified three transcript variants that encode two different isoforms. Pseudogenes corresponding to this gene are found on chromosomes 4q, 6p, 6q, 7p, and 15q.^[4]

Further reading

• Bonaldo MF, Lennon G, Soares MB . Normalization and subtraction: two approaches to facilitate gene discovery. . Genome Res. . 6 . 9 . 791–806 . 1997 . 8889548 . 10.1101/gr.6.9.791 . free .
• Wiemann S, Weil B, Wellenreuther R, etal . Toward a catalog of human genes and proteins: sequencing and analysis of 500 novel complete protein coding human cDNAs. . Genome Res. . 11 . 3 . 422–35 . 2001 . 11230166 . 10.1101/gr.GR1547R . 311072 .
• Kenmochi N, Suzuki T, Uechi T, etal . The human mitochondrial ribosomal protein genes: mapping of 54 genes to the chromosomes and implications for human disorders. . Genomics . 77 . 1–2 . 65–70 . 2001 . 11543634 . 10.1006/geno.2001.6622 .
• Koc EC, Burkhart W, Blackburn K, etal . The large subunit of the mammalian mitochondrial ribosome. Analysis of the complement of ribosomal proteins present. . J. Biol. Chem. . 276 . 47 . 43958–69 . 2001 . 11551941 . 10.1074/jbc.M106510200 . free .
• Strausberg RL, Feingold EA, Grouse LH, etal . Generation and initial analysis of more than 15,000 full-length human and mouse cDNA sequences. . Proc. Natl. Acad. Sci. U.S.A. . 99 . 26 . 16899–903 . 2003 . 12477932 . 10.1073/pnas.242603899 . 139241 . 2002PNAS...9916899M . free .
• Zhang Z, Gerstein M . Identification and characterization of over 100 mitochondrial ribosomal protein pseudogenes in the human genome. . Genomics . 81 . 5 . 468–80 . 2003 . 12706105 . 10.1016/S0888-7543(03)00004-1 .
• Ota T, Suzuki Y, Nishikawa T, etal . Complete sequencing and characterization of 21,243 full-length human cDNAs. . Nat. Genet. . 36 . 1 . 40–5 . 2004 . 14702039 . 10.1038/ng1285 . free .
• Gerhard DS, Wagner L, Feingold EA, etal . The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC). . Genome Res. . 14 . 10B . 2121–7 . 2004 . 15489334 . 10.1101/gr.2596504 . 528928 .
• Stelzl U, Worm U, Lalowski M, etal . A human protein-protein interaction network: a resource for annotating the proteome. . Cell . 122 . 6 . 957–68 . 2005 . 16169070 . 10.1016/j.cell.2005.08.029 . 11858/00-001M-0000-0010-8592-0 . 8235923 . free .

Notes and References

1. Cavdar Koc E, Burkhart W, Blackburn K, Moseley A, Spremulli LL . The small subunit of the mammalian mitochondrial ribosome. Identification of the full complement of ribosomal proteins present . J Biol Chem . 276 . 22 . 19363–74 . May 2001 . 11279123 . 10.1074/jbc.M100727200 . free . 10.1.1.501.8919 .
2. Zhang QH, Ye M, Wu XY, Ren SX, Zhao M, Zhao CJ, Fu G, Shen Y, Fan HY, Lu G, Zhong M, Xu XR, Han ZG, Zhang JW, Tao J, Huang QH, Zhou J, Hu GX, Gu J, Chen SJ, Chen Z . Cloning and functional analysis of cDNAs with open reading frames for 300 previously undefined genes expressed in CD34+ hematopoietic stem/progenitor cells . Genome Res . 10 . 10 . 1546–60 . Nov 2000 . 11042152 . 310934 . 10.1101/gr.140200 .
3. Web site: Entrez Gene: MRPL42 mitochondrial ribosomal protein L42.
4. Web site: Entrez Gene: MRPL42 mitochondrial ribosomal protein L42.