Identification of multiple forms of 180-kDa ribosome receptor in human cells.
Herein, we describe the analysis and mapping of cDNA clones encoding variant forms of the human homolog of the canine 180-kDa ribosome receptor (p180). One form, similar to the chicken ES/130 homolog, possesses a large uninterrupted C-terminal region composed predominantly of heptad repeats predicted to form an alpha-helical double-stranded coiled-coil rod. Other forms contain in addition a 10-amino acid consensus motif, NQGKKAEGAQ, repeated up to 54 times in tandem close to the N-terminus. Such repeats in canine p180 represent a ribosome-binding domain. The cDNA hybridized to a major 6-kb transcript in all tissues examined, where very high expression was observed in tissues that carry out a high level of secretion such as pancreas, liver, and placenta. The ES130/p180 gene was mapped to chromosome 20p12, and a potential pseudogene appears to reside on chromosome 7. In summary, the data suggest that p180 exists in humans in different forms because of complete removal of tandem repeats, or partial intraexonic splicing, creating different repeat lengths with potentially novel ribosome-binding characteristics.
Langley
R
R
Department of Molecular Medicine, School of Medicine and Health Sciences, University of Auckland, NZ.
Leung
E
E
Morris
C
C
Berg
R
R
McDonald
M
M
Weaver
A
A
Parry
D A
DA
Ni
J
J
Su
J
J
Gentz
R
R
Spurr
N
N
Krissansen
G W
GW
D017398:Alternative Splicing; D000818:Animals; D030161:Avian Proteins; D002460:Cell Line; D002645:Chickens; D002874:Chromosome Mapping; D002890:Chromosomes, Human, Pair 20 / Q000235:genetics; D004285:Dogs; D004730:Endothelium, Vascular; D016326:Extracellular Matrix Proteins / Q000737:chemistry; D018922:HL-60 Cells; D006801:Humans; D008970:Molecular Weight; D017433:Protein Structure, Secondary; D012333:RNA, Messenger / Q000378:metabolism; D018160:Receptors, Cytoplasmic and Nuclear / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification; D012091:Repetitive Sequences, Nucleic Acid; D012270:Ribosomes / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D014158:Transcription, Genetic; D014471:Umbilical Veins
D030161:Avian Proteins; C081857:ES-130 protein, Gallus gallus; D016326:Extracellular Matrix Proteins; D012333:RNA, Messenger; D018160:Receptors, Cytoplasmic and Nuclear; C065526:ribosome receptor