The Surf-6 gene of the mouse surfeit locus encodes a novel nucleolar protein.
The Surfeit locus contains the tightest cluster of mammalian genes so far described. The five Surfeit genes (Surf-1 to -5) that have been previously isolated and characterized do not share any DNA or amino acid sequence homology. These Surfeit genes appear to be housekeeping genes, with the Surf-3 gene encoding the 1.7a ribosomal protein and the Surf-4 gene encoding an integral membrane protein most likely associated with the endoplasmic reticulum. In this work, we have isolated the Surf-6 gene, a sixth member of the Surfeit locus. The Surf-6 gene contains four exons spanning a genomic region of 14 kb and specifies a mRNA of 2,571 bases. Surf-6 has features common to housekeeping genes because its transcript is present in every tissue tested, its 5' end is associated with a CpG-rich island, and its promoter does not contain a canonical TATA box. The Surf-6 long open reading frame encodes a novel highly basic polypeptide of 355 amino acids (28% Arg and Lys). By immunofluorescence and immunoblot analyses, the Surf-6 protein has been found to be located in the nucleolus and by immunocytochemical microscopy to be localized predominantly in the nucleolar granular component, a structure that is involved in ribosome maturation. These results indicate that the novel Surf-6 gene is involved in a nucleolar function.
Magoulas
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Eukaryotic Gene Organisation and Expression Laboratory, Imperial Cancer Research Fund, Lincoln's Inn Fields, London, UK.
Fried
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D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D002466:Cell Nucleolus / Q000378:metabolism* / Q000648:ultrastructure; D018076:DNA, Complementary; D005455:Fluorescent Antibody Technique; D015870:Gene Expression; D015151:Immunoblotting; D007939:Leukemia L1210 / Q000378:metabolism; D008322:Mammals; D051379:Mice / Q000235:genetics*; D016253:Microscopy, Immunoelectron; D008969:Molecular Sequence Data; D005810:Multigene Family; D009687:Nuclear Proteins / Q000032:analysis / Q000096:biosynthesis* / Q000235:genetics*; D009928:Organ Specificity; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000032:analysis / Q000096:biosynthesis; D015183:Restriction Mapping; D012270:Ribosomes / Q000502:physiology; D014158:Transcription, Genetic
D018076:DNA, Complementary; D009687:Nuclear Proteins; D012333:RNA, Messenger; C098938:Surf6 protein, mouse