|Budget Amount *help
¥2,200,000 (Direct Cost : ¥2,200,000)
Fiscal Year 1991 : ¥500,000 (Direct Cost : ¥500,000)
Fiscal Year 1990 : ¥600,000 (Direct Cost : ¥600,000)
Fiscal Year 1989 : ¥1,100,000 (Direct Cost : ¥1,100,000)
(1)Complementary DNA cloning.
We isolated CDNA clones for two rat ribososomal proteins and four chicken ribosomal proteins. The CDNAs were not only used as probes in gene cloning but also sequenced to provide information on the structure, function and evolution of the ribosomes.
We isolated the clones of four kinds of ribosomal proteins genes, L5, L7a, L30, and L37a, from a chicken genomic library and determined the entire nucleotide sequences of the genes, expanding about 8.5, 4.5, 4.0, and 3.5 kilobases, respectively.
(3)Features in the promoter region of the ribosomal protein genes.
These genes do not have either canonical CAAT box or TATA box. There are many CpG dimers concentrated around the transcription initiation site and several GC boxes, known as the binding sites of the transcription factor Spl, in the promoter region. These findings are common to many other house keeping genes.
We could not found specific nucleotide sequence that is common to promoter regions of all four genes and seems to be concerned in transcriptional regulation. But there are several candidates for the binding subs of the transcriptional regulation factors and/or initiation factors common to two or three genes. The sequence similar to the internal transcriptional control region of 5S RNA gene was also found in the promoter region of the gene of L5, the 5S RNA binding protein.
These findings suggest that the expression of ribosomal protein gene is regulated by complicated control mechanisms. The function of these candidates of regulatory elements is being analyzed by CAT assay and the binding assay of nuclear extract.