scholarly journals The two alpha-tubulin genes of Chlamydomonas reinhardi code for slightly different proteins.

1985 ◽  
Vol 5 (9) ◽  
pp. 2389-2398 ◽  
Author(s):  
C D Silflow ◽  
R L Chisholm ◽  
T W Conner ◽  
L P Ranum

Full-length cDNA clones corresponding to the transcripts of the two alpha-tubulin genes in Chlamydomonas reinhardi were isolated. DNA sequence analysis of the cDNA clones and cloned gene fragments showed that each gene contains 1,356 base pairs of coding sequence, predicting alpha-tubulin products of 451 amino acids. Of the 27 nucleotide differences between the two genes, only two result in predicted amino acid differences between the two gene products. In the more divergent alpha 2 gene, a leucine replaces an arginine at amino acid 308, and a valine replaces a glycine at amino acid 366. The results predicted that two alpha-tubulin proteins with different net charges are produced as primary gene products. The predicted amino acid sequences are 86 and 70% homologous with alpha-tubulins from rat brain and Schizosaccharomyces pombe, respectively. Each gene had two intervening sequences, located at identical positions. Portions of an intervening sequence highly conserved between the two beta-tubulin genes are also found in the second intervening sequence of each of the alpha genes. These results, together with our earlier report of the beta-tubulin sequences in C. reinhardi, present a picture of the total complement of genetic information for tubulin in this organism.

1985 ◽  
Vol 5 (9) ◽  
pp. 2389-2398
Author(s):  
C D Silflow ◽  
R L Chisholm ◽  
T W Conner ◽  
L P Ranum

Full-length cDNA clones corresponding to the transcripts of the two alpha-tubulin genes in Chlamydomonas reinhardi were isolated. DNA sequence analysis of the cDNA clones and cloned gene fragments showed that each gene contains 1,356 base pairs of coding sequence, predicting alpha-tubulin products of 451 amino acids. Of the 27 nucleotide differences between the two genes, only two result in predicted amino acid differences between the two gene products. In the more divergent alpha 2 gene, a leucine replaces an arginine at amino acid 308, and a valine replaces a glycine at amino acid 366. The results predicted that two alpha-tubulin proteins with different net charges are produced as primary gene products. The predicted amino acid sequences are 86 and 70% homologous with alpha-tubulins from rat brain and Schizosaccharomyces pombe, respectively. Each gene had two intervening sequences, located at identical positions. Portions of an intervening sequence highly conserved between the two beta-tubulin genes are also found in the second intervening sequence of each of the alpha genes. These results, together with our earlier report of the beta-tubulin sequences in C. reinhardi, present a picture of the total complement of genetic information for tubulin in this organism.


1986 ◽  
Vol 6 (11) ◽  
pp. 3711-3721
Author(s):  
P J Schatz ◽  
L Pillus ◽  
P Grisafi ◽  
F Solomon ◽  
D Botstein

Two alpha-tubulin genes from the budding yeast Saccharomyces cerevisiae were identified and cloned by cross-species DNA homology. Nucleotide sequencing studies revealed that the two genes, named TUB1 and TUB3, encoded gene products of 447 and 445 amino acids, respectively, that are highly homologous to alpha-tubulins from other species. Comparison of the sequences of the two genes revealed a 19% divergence between the nucleotide sequences and a 10% divergence between the amino acid sequences. Each gene had a single intervening sequence, located at an identical position in codon 9. Cell fractionation studies showed that both gene products were present in yeast microtubules. These two genes, along with the TUB2 beta-tubulin gene, probably encode the entire complement of tubulin in budding yeast cells.


1984 ◽  
Vol 4 (12) ◽  
pp. 2686-2696 ◽  
Author(s):  
J Youngblom ◽  
J A Schloss ◽  
C D Silflow

The two beta-tubulin genes of the unicellular green alga Chlamydomonas reinhardtii are expressed coordinately after deflagellation and produce two transcripts of 2.1 and 2.0 kilobases. Full-length cDNA clones corresponding to the transcript of each gene were isolated. DNA sequences were obtained from the cDNA clones and from cloned tubulin gene fragments. Both genes contained 1,332 base pairs of coding sequence, with only 19 nucleotide differences between the genes. Because all the differences occurred at the third base position of a codon and did not change the predicted amino acid sequence, we concluded that both beta-tubulin genes code for the same protein of 443 amino acids. The predicted amino acid sequence is 89 and 72% homologous with beta-tubulins from chicken and yeast cells, respectively. Each gene had three intervening sequences, which occurred at identical positions. Although the first two intervening sequences were not conserved between the two genes, the nucleotide sequence of the third intervening sequence was 89% conserved between the genes. The codon usage in the tubulin genes of C. reinhardtii was very biased: only 37 different codons were used. Striking differences occurred between the codons used in these nuclear genes and C. reinhardtii chloroplast genes.


1981 ◽  
Vol 1 (12) ◽  
pp. 1125-1137
Author(s):  
D Alexandraki ◽  
J V Ruderman

We analyzed the multiplicity, heterogeneity, and organization of the genes encoding the alpha and beta tubulins in the sea urchin Lytechinus pictus by using cloned complementary deoxyribonucleic acid (cDNA) and genomic tubulin sequences. cDNA clones were constructed by using immature spermatogenic testis polyadenylic acid-containing ribonucleic acid as a template. alpha- and beta-tubulin clones were identified by hybrid selection and in vitro translation of the corresponding messenger ribonucleic acids, followed by immunoprecipitation and two-dimensional gel electrophoresis of the translation products. The alpha cDNA clone contains a sequence that encodes the 48 C-terminal amino acids of alpha tubulin and 104 base pairs of the 3' nontranslated portion of the messenger ribonucleic acid. The beta cDNA insertion contains the coding sequence for the 100-C terminal amino acids of beta tubulin and 83 pairs of the 3' noncoding sequence. Hybrid selections performed at different criteria demonstrated the presence of several heterogeneous, closely related tubulin messenger ribonucleic acids, suggesting the existence of heterogeneous alpha- and beta-tubulin genes. Hybridization analyses indicated that there are at least 9 to 13 sequences for each of the two tubulin gene families per haploid genome. Hybridization of the cDNA probes to both total genomic DNA and cloned germline DNA fragments gave no evidence for close physical linkage of alpha-tubulin genes with beta-tubulin genes at the DNA level. In contrast, these experiments indicated that some genes within the same family are clustered.


1981 ◽  
Vol 1 (12) ◽  
pp. 1125-1137 ◽  
Author(s):  
D Alexandraki ◽  
J V Ruderman

We analyzed the multiplicity, heterogeneity, and organization of the genes encoding the alpha and beta tubulins in the sea urchin Lytechinus pictus by using cloned complementary deoxyribonucleic acid (cDNA) and genomic tubulin sequences. cDNA clones were constructed by using immature spermatogenic testis polyadenylic acid-containing ribonucleic acid as a template. alpha- and beta-tubulin clones were identified by hybrid selection and in vitro translation of the corresponding messenger ribonucleic acids, followed by immunoprecipitation and two-dimensional gel electrophoresis of the translation products. The alpha cDNA clone contains a sequence that encodes the 48 C-terminal amino acids of alpha tubulin and 104 base pairs of the 3' nontranslated portion of the messenger ribonucleic acid. The beta cDNA insertion contains the coding sequence for the 100-C terminal amino acids of beta tubulin and 83 pairs of the 3' noncoding sequence. Hybrid selections performed at different criteria demonstrated the presence of several heterogeneous, closely related tubulin messenger ribonucleic acids, suggesting the existence of heterogeneous alpha- and beta-tubulin genes. Hybridization analyses indicated that there are at least 9 to 13 sequences for each of the two tubulin gene families per haploid genome. Hybridization of the cDNA probes to both total genomic DNA and cloned germline DNA fragments gave no evidence for close physical linkage of alpha-tubulin genes with beta-tubulin genes at the DNA level. In contrast, these experiments indicated that some genes within the same family are clustered.


1986 ◽  
Vol 6 (11) ◽  
pp. 3711-3721 ◽  
Author(s):  
P J Schatz ◽  
L Pillus ◽  
P Grisafi ◽  
F Solomon ◽  
D Botstein

Two alpha-tubulin genes from the budding yeast Saccharomyces cerevisiae were identified and cloned by cross-species DNA homology. Nucleotide sequencing studies revealed that the two genes, named TUB1 and TUB3, encoded gene products of 447 and 445 amino acids, respectively, that are highly homologous to alpha-tubulins from other species. Comparison of the sequences of the two genes revealed a 19% divergence between the nucleotide sequences and a 10% divergence between the amino acid sequences. Each gene had a single intervening sequence, located at an identical position in codon 9. Cell fractionation studies showed that both gene products were present in yeast microtubules. These two genes, along with the TUB2 beta-tubulin gene, probably encode the entire complement of tubulin in budding yeast cells.


1984 ◽  
Vol 4 (12) ◽  
pp. 2686-2696
Author(s):  
J Youngblom ◽  
J A Schloss ◽  
C D Silflow

The two beta-tubulin genes of the unicellular green alga Chlamydomonas reinhardtii are expressed coordinately after deflagellation and produce two transcripts of 2.1 and 2.0 kilobases. Full-length cDNA clones corresponding to the transcript of each gene were isolated. DNA sequences were obtained from the cDNA clones and from cloned tubulin gene fragments. Both genes contained 1,332 base pairs of coding sequence, with only 19 nucleotide differences between the genes. Because all the differences occurred at the third base position of a codon and did not change the predicted amino acid sequence, we concluded that both beta-tubulin genes code for the same protein of 443 amino acids. The predicted amino acid sequence is 89 and 72% homologous with beta-tubulins from chicken and yeast cells, respectively. Each gene had three intervening sequences, which occurred at identical positions. Although the first two intervening sequences were not conserved between the two genes, the nucleotide sequence of the third intervening sequence was 89% conserved between the genes. The codon usage in the tubulin genes of C. reinhardtii was very biased: only 37 different codons were used. Striking differences occurred between the codons used in these nuclear genes and C. reinhardtii chloroplast genes.


1993 ◽  
Vol 291 (3) ◽  
pp. 787-792 ◽  
Author(s):  
R Z Zhang ◽  
T C Pan ◽  
R Timpl ◽  
M L Chu

cDNA clones encoding the alpha 1, alpha 2 and alpha 3 chains of mouse collagen VI have been isolated by screening cDNA libraries with the corresponding human probes. The composite cDNAs for the alpha 1, alpha 2, and alpha 3 chains are 2.5, 1.6 and 2.9 kb in size respectively. The alpha 1 and alpha 2 cDNAs encode the C-terminal portions of the chains as well as the entire 3′-untranslated regions, while the alpha 3 cDNAs encode a central segment of 959 amino acids flanking the triple-helical domain. The deduced amino acid sequences share 86-88% identity with the human counterparts and 67-73% identity with the chicken equivalents. Alignment of the deduced amino acid sequences of mouse, human and chicken collagens reveal that the key features of the protein, including the cysteine residues, imperfections in the Gly-Xaa-Xaa regions, Arg-Gly-Asp sequences and potential N-glycosylation sites, are mostly conserved.


1994 ◽  
Vol 299 (2) ◽  
pp. 545-552 ◽  
Author(s):  
Y Deyashiki ◽  
A Ogasawara ◽  
T Nakayama ◽  
M Nakanishi ◽  
Y Miyabe ◽  
...  

Human liver contains two dihydrodiol dehydrogenases, DD2 and DD4, associated with 3 alpha-hydroxysteroid dehydrogenase activity. We have raised polyclonal antibodies that cross-reacted with the two enzymes and isolated two 1.2 kb cDNA clones (C9 and C11) for the two enzymes from a human liver cDNA library using the antibodies. The clones of C9 and C11 contained coding sequences corresponding to 306 and 321 amino acid residues respectively, but lacked 5′-coding regions around the initiation codon. Sequence analyses of several peptides obtained by enzymic and chemical cleavages of the two purified enzymes verified that the C9 and C11 clones encoded DD2 and DD4 respectively, and further indicated that the sequence of DD2 had at least additional 16 residues upward from the N-terminal sequence deduced from the cDNA. There was 82% amino acid sequence identity between the two enzymes, indicating that the enzymes are genetic isoenzymes. A computer-based comparison of the cDNAs of the isoenzymes with the DNA sequence database revealed that the nucleotide and amino acid sequences of DD2 and DD4 are virtually identical with those of human bile-acid binder and human chlordecone reductase cDNAs respectively.


1983 ◽  
Vol 3 (6) ◽  
pp. 1070-1076
Author(s):  
S M Landfear ◽  
D McMahon-Pratt ◽  
D F Wirth

The arrangement of developmentally regulated alpha- and beta-tubulin genes has been studied in the parasitic protozoan Leishmania enriettii by using Southern blot hybridization analysis. The alpha-tubulin genes occur in a tandem repeat whose monomeric unit may be represented by a 2-kilobase PstI fragment. Similarly, the beta-tubulin genes probably occur in a separate tandem repeat consisting of approximately 4-kilobase units unlinked to the alpha-tubulin repeats.


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