Cloning and analysis of the human S13 ribosomal protein cDNA

Abstract

In a hope to isolate genes whose expression was elevated in colon cancer cells, we used a plus/minus screening of a rat colon carcinoma cDNA library. We were thus able to isolate a cDNA clone (B9) encoding the rat S13 ribosomal protein (1). The corresponding mRNA is-30-fold more abundant in the cancer cells than in normal colon, and 50-fold more important in lung metastasis than in normal lung. The expression level of this gene was found to be closely correlated with the growth rate of rat cell lines (1). Unfortunately, the B9 probe was short, and did not hybridize to RNA prepared from human tissues. In order to obtain longer clones encoding the rat S13 ribosomal protein we first rescreened the PROb cDNA library. A longer insert was then used to screen a cDNA library prepared from the T-84 colonic epithelial cell line constructed in the Uni-ZAP XR vector (Stratagene, La Jolla, CA). Inserts were excised with helper phage R408 to generate subclones in the pBluescript plasmid and sequenced by the dideoxy-chain termination method (2) using T7 DNA polymerase. The final sequences were determined from both strands. This cDNA contains 548 nucleotides and includes a 5' noncoding sequence of 32 nucleotides, an open reading frame of 456 nucleotides, a 3' noncoding sequence of 60 nucleotides, followed by a 19 bp polyA tail (Figure 1). The presumed polyadenylation signal, AATAAA, is located at bases 509-514. The nucleotide sequence in the coding region differs from the rat S13 ribosomal protein sequence (3) in the first position in 6 codons and in the third position in 52 codons. It encodes a sequence of 151 aminoacids which is identical to the rat protein. This highly conserved primary structure of ribosomal proteins across species has been observed for other ribosomal proteins (4, 5). Northern blot analysis revealed that the size of the human S13 ribosomal protein mRNA is approximately 600 bp. This probe hybridized to 8-10 genomic DNA fragments, probably representing one (or a few) functional S13 gene and a family of nonfunctional pseudogenes, as it has been shown for many other ribosomal protein genes (6, 7).

Transcriptional activation of the mouse Necl-5/Tage4/PVR/CD155 gene by fibroblast growth factor or oncogenic Ras through the Raf–MEK–ERK–AP-1 pathway

“…Necl-5/Tage4/poliovirus receptor (PVR)/CD155 is an immunoglobulin (Ig)-like molecule having a domain structure consisting of one extracellular region with three Ig-like loops, one transmembrane region, and one cytoplasmic region (Mendelsohn et al, 1989;Koike et al, 1990;Chadeneau et al, 1994Chadeneau et al, , 1996. Human PVR/ CD155 was originally identified as the human PVR (Mendelsohn et al, 1989;Koike et al, 1990), whereas Tage4 was originally identified as the product of a gene overexpressed in rat and mouse colon carcinoma (Chadeneau et al, 1994(Chadeneau et al, , 1996.…”

“…Human PVR/ CD155 was originally identified as the human PVR (Mendelsohn et al, 1989;Koike et al, 1990), whereas Tage4 was originally identified as the product of a gene overexpressed in rat and mouse colon carcinoma (Chadeneau et al, 1994(Chadeneau et al, , 1996. PVR/CD155 has subsequently been shown to be overexpressed in human colorectal carcinoma and malignant glioma (Gromeier et al, 2000;Masson et al, 2001).…”

Nectin-like Molecule-5/Tage4 Enhances Cell Migration in an Integrin-dependent, Nectin-3-independent Manner

“…These include Necl-1/ TSLL1/SynCAM3 (16,17), Necl-2/IGSF4/RA175/SgIGSF/ TSLC1/SynCAM1 (17-21), Necl-3/similar to NECL3/SynCAM2 (17), Necl-4/TSLL2/SynCAM4 (16,17), and Necl-5/Tage4/human poliovirus receptor (PVR)/CD155 (22)(23)(24)(25). The domain structures of this group of molecules are similar to those of nectins, but they do not bind afadin (11,26).…”

“…Tage4 was originally identified to be the product of a gene overexpressed in rat and mouse colon carcinoma (24,25). The Tage4 gene has been mapped to rat chromosome 1q22 (27) and mouse 7A2-B1 (28).…”

“…The Tage4 gene has been mapped to rat chromosome 1q22 (27) and mouse 7A2-B1 (28). Northern blot analysis has revealed that the Tage4 mRNA is expressed in normal adult rat and mouse tissues to small extents (24,25). Tage4 has been shown to mediate entry of porcine pseudorabies virus and bovine herpesvirus 1 (29).…”