The reference OMIM entry for this protein is 603634

Ribosomal protein l5; rpl5

DESCRIPTION

The mammalian ribosome is a macromolecular assembly of 4 RNA species (rRNAs; see 180450) and approximately 80 different proteins, including RPL5 (Kenmochi et al., 1998).

CLONING

By searching sequence databases with the partial sequences of randomly selected cDNAs from a human colorectal cDNA library, Frigerio et al. (1995) identified cDNAs encoding homologs of rat ribosomal proteins S5 (RPS5; 603630), S9 (RPS9; 603631), S10 (RPS10; 603632), S29 (RPS29; 603633), L5 (RPL5), L21 (RPL21; 603636), L27a (RPL27A; 603637), and L28 (RPL28; 603638). Frigerio et al. (1995) completed the cDNA sequences of these human ribosomal proteins. The deduced 297-amino acid human RPL5 differs from rat Rpl5 by 4 amino acids. Northern blot analysis suggested variable expression of RPL5 in colorectal cancers compared to adjacent normal tissues, although no correlation between the level of expression and the severity of the disease was found. By Northern blot analysis using a rat Rpl5 probe, Pogue-Geile et al. (1991) demonstrated overexpression of RPL5 in human colorectal tumors and polyps relative to matched normal colonic mucosa. RPL5 is expressed as a 1.2-kb transcript.

GENE STRUCTURE

Boria et al. (2010) stated that the RPL5 gene contains 8 exons and spans 9.8 kb.

MAPPING

In both human and mouse, Qu et al. (1994) found that the U21 snoRNA (603635) is encoded in intron 5 of the RPL5 gene. By somatic cell hybrid and radiation hybrid mapping analyses, Kenmochi et al. (1998) mapped the RPL5 gene to chromosome 1p. Boria et al. (2010) stated that the RPL5 gene maps to chromosome 1p22.1.

GENE FUNCTION

Impeding ribosomal biogenesis generates ribosomal stress that activates p53 (TP53; 191170) to stop cell growth. Dai et al. (2006) stated that the ribosomal proteins L5, L11 (RPL11; 604175), and L23 (RPL23; 603662) interact with MDM2 (164785) and inhibit MDM2-mediated p53 ubiquitination and degradation in response to ribosomal stress. They found that L5 and L23 inhibited ubiquitination of both p53 and MDM2 in human cell lines. In contrast, L11 inhibited proteasome-mediated degradation of ubiquitinated MDM2, but not p53, resulting in stabilization of p53. Ribosomal protein L5 binds 5S rRNA (see 180420) to form the ribosomal 5S RNA-protein (5S rRNP) complex. Using polysome assays and crosslinking experiments with in vitro-translated human mRNA, Lin et al. (2001) found that the 5S rRNP complex formed only if 5S rRNA was present at the beginning of L5 translation. The 5S rRNP complex was not observed if 5S rRNA was added after completion of L5 synthesis. Mutation analysis revealed that residues 35 through 50 of L5 engaged in the interaction, but the remainder of the L5 protein was required for stable formation of the 5S rRNP complex. Association of L5 with 5S rRNA significantly enhanced L5 nuclear import into injected Xenopus oocytes.

MOLECULAR GENETICS

Gazda et al. (2008) screened 196 probands with Diamond-Blackfan anemia (see DBA6, 612561) for mutations in 25 genes encoding ribosomal proteins and identified 15 different mutations in the RPL5 gene in 18 probands and 6 additional family members (see, e.g., 603634.0001-603634.0006); 3 of the mutation-positive patients were from the family with DBA originally described by Aase and Smith (1969) (see 603634.0005). The mutations segregated with disease in multiplex families and were not found in at least 150 controls. Analysis of pre-rRNAs from lymphobl ... More on the omim web site

Subscribe to this protein entry history

July 4, 2019: Protein entry updated
Automatic update: OMIM entry 603634 was added.

Oct. 19, 2018: Additional information
Initial protein addition to the database. This entry was referenced in Bryk and co-workers. (2017).