3 EXPRESSED SEQUENCES WITHIN THE HUMAN BETA-TUBULIN MULTIGENE FAMILY EACH DEFINE A DISTINCT ISOTYPE
3 EXPRESSED SEQUENCES WITHIN THE HUMAN BETA-TUBULIN MULTIGENE FAMILY EACH DEFINE A DISTINCT ISOTYPE
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DOI：
10.1016/0022-2836(85)90023-3
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发表时间：
1985-01-01
影响因子：
5.6
通讯作者：
COWAN, NJ
中科院分区：
文献类型：
--
作者：
LEWIS, SA;GILMARTIN, ME;COWAN, NJ
The isolation and complete sequence of a novel expressed human .beta.-tubulin gene (.beta.2) is described. The sequence is compared with that of 2 other expressed human .beta.-tubulin genes (M40 and 5.beta.). All are encoded by 4 exons. Though the boundaries of each exon are absolutely conserved among the 3 genes, the intervening sequences differ considerably in size and sequence content. Two of the genes (M40 and 5.beta.) contain 1 (M40) or 10 (5.beta.) members of the middle repetitive Alu family sequences within one of their intervening sequences. Comparison of the amino acid sequences encoded by each gene reveals a high level of homology overall, though there is significant divergence between the carboxyl termini of 2 of the genes. The pattern of expression of each .beta.-tubulin gene was studied in several different human cell lines using unique non-crosshybridizing probes derived from the 3'' untranslated regions. Two of the genes, M40 and .beta.2, are expressed at varying levels in all of the cell lines examined, though the level of expression of one of these genes parallels the other in most cases. The 3rd gene, 5.beta., is detectably expressed only in cells of neural origin. Distinct human .beta.-tubulin isotypes are encoded by genes whose exon size and number was conserved evolutionarily, but whose pattern of expression may be regulated either co-ordinatley or uniquely. Of the .apprx. 15 sequences contained in the human .beta.-tubulin multigene family, 9 were now sequenced fully. The overall composition of the multigene family and the evolutionary relationships among its various members are discussed.
