Expression of a gene family in the dimorphic fungus Mucor racemosus which exhibits striking similarity to human ras genes

1990 ◽  
Vol 10 (12) ◽  
pp. 6654-6663
Author(s):  
W L Casale ◽  
D G Mcconnell ◽  
S Y Wang ◽  
Y J Lee ◽  
J E Linz
Keyword(s):  
Amino Acid ◽  
Cell Development ◽  
Amino Acid Sequences ◽  
Model Systems ◽  
Striking Similarity ◽  
Ras Proteins ◽  
Mucor Racemosus ◽  
Dimorphic Fungus ◽  
Transcript Accumulation ◽  
Ras Genes

Sporulation, spore germination, and yeast-hypha dimorphism in the filamentous fungus Mucor racemosus provide useful model systems to study cell development in eucaryotic cells. Three RAS genes (MRAS1, MRAS2, and MRAS3) from M. racemosus have been cloned, and their nucleotide sequences have been determined. The predicted amino acid sequences and the sizes of the three MRAS proteins exhibit a high degree of similarity with other ras proteins, including that encoded by H-ras, which have been implicated in regulation of proliferation and development in eucaryotic cells by mediating signal transduction pathways. The MRAS proteins show conservation of functional domains proposed for ras proteins, including guanine nucleotide interaction domains, an effector domain, a binding epitope for neutralizing antibody Y13-259, and the COOH-terminal CAAX box, which is a site of thiocylation and membrane attachment. Amino acid sequences unique to each MRAS protein occur adjacent to the CAAX box, consistent with the location of the hypervariable region in other ras proteins. Northern (RNA) analysis was used to study expression of the three MRAS genes in relation to cell development. Gene-specific probes for two of these genes, MRAS1 and MRAS3, hybridized to different 1.3-kb mRNA transcripts. The accumulation of these transcripts depended on the developmental stage, and this pattern was different between the two MRAS genes. No transcript for MRAS2 was detected in the developmental stages examined. The unique patterns of MRAS transcript accumulation suggest that individual MRAS genes and proteins may play distinct roles in cell growth or development.

scholarly journals Expression of a gene family in the dimorphic fungus Mucor racemosus which exhibits striking similarity to human ras genes.

1990 ◽  
Vol 10 (12) ◽  
pp. 6654-6663 ◽  
Author(s):  
W L Casale ◽  
D G Mcconnell ◽  
S Y Wang ◽  
Y J Lee ◽  
J E Linz
Keyword(s):  
Amino Acid ◽  
Cell Development ◽  
Amino Acid Sequences ◽  
Model Systems ◽  
Striking Similarity ◽  
Ras Proteins ◽  
Mucor Racemosus ◽  
Dimorphic Fungus ◽  
Transcript Accumulation ◽  
Ras Genes

Sporulation, spore germination, and yeast-hypha dimorphism in the filamentous fungus Mucor racemosus provide useful model systems to study cell development in eucaryotic cells. Three RAS genes (MRAS1, MRAS2, and MRAS3) from M. racemosus have been cloned, and their nucleotide sequences have been determined. The predicted amino acid sequences and the sizes of the three MRAS proteins exhibit a high degree of similarity with other ras proteins, including that encoded by H-ras, which have been implicated in regulation of proliferation and development in eucaryotic cells by mediating signal transduction pathways. The MRAS proteins show conservation of functional domains proposed for ras proteins, including guanine nucleotide interaction domains, an effector domain, a binding epitope for neutralizing antibody Y13-259, and the COOH-terminal CAAX box, which is a site of thiocylation and membrane attachment. Amino acid sequences unique to each MRAS protein occur adjacent to the CAAX box, consistent with the location of the hypervariable region in other ras proteins. Northern (RNA) analysis was used to study expression of the three MRAS genes in relation to cell development. Gene-specific probes for two of these genes, MRAS1 and MRAS3, hybridized to different 1.3-kb mRNA transcripts. The accumulation of these transcripts depended on the developmental stage, and this pattern was different between the two MRAS genes. No transcript for MRAS2 was detected in the developmental stages examined. The unique patterns of MRAS transcript accumulation suggest that individual MRAS genes and proteins may play distinct roles in cell growth or development.

scholarly journals Genes for low-molecular-weight heat shock proteins of soybeans: sequence analysis of a multigene family.

1985 ◽  
Vol 5 (12) ◽  
pp. 3417-3428 ◽  
Author(s):  
R T Nagao ◽  
E Czarnecka ◽  
W B Gurley ◽  
F Schöffl ◽  
J L Key
Keyword(s):  
Molecular Weight ◽  
Amino Acid ◽  
Heat Shock ◽  
Dna Sequences ◽  
Regulatory Element ◽  
Amino Acid Sequences ◽  
Striking Similarity ◽  
Low Molecular Weight ◽  
Genes Encoding ◽  
Flanking Regions

Soybeans, Glycine max, synthesize a family of low-molecular-weight heat shock (HS) proteins in response to HS. The DNA sequences of two genes encoding 17.5- and 17.6-kilodalton HS proteins were determined. Nuclease S1 mapping of the corresponding mRNA indicated multiple start termini at the 5' end and multiple stop termini at the 3' end. These two genes were compared with two other soybean HS genes of similar size. A comparison among the 5' flanking regions encompassing the presumptive HS promoter of the soybean HS-protein genes demonstrated this region to be extremely homologous. Analysis of the DNA sequences in the 5' flanking regions of the soybean genes with the corresponding regions of Drosophila melanogaster HS-protein genes revealed striking similarity between plants and animals in the presumptive promoter structure of thermoinducible genes. Sequences related to the Drosophila HS consensus regulatory element were found 57 to 62 base pairs 5' to the start of transcription in addition to secondary HS consensus elements located further upstream. Comparative analysis of the deduced amino acid sequences of four soybean HS proteins illustrated that these proteins were greater than 90% homologous. Comparison of the amino acid sequence for soybean HS proteins with other organisms showed much lower homology (less than 20%). Hydropathy profiles for Drosophila, Xenopus, Caenorhabditis elegans, and G. max HS proteins showed a similarity of major hydrophilic and hydrophobic regions, which suggests conservation of functional domains for these proteins among widely dispersed organisms.

scholarly journals Formation of Pyrazines in Maillard Model Systems: Effects of Structures of Lysine-Containing Dipeptides/Tripeptides

Foods ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 273
Author(s):  
Furong Wang ◽  
Hailiang Shen ◽  
Ting Liu ◽  
Xi Yang ◽  
Yali Yang ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Sunflower Seed ◽  
Seed Oil ◽  
Reaction System ◽  
Amino Acid Sequences ◽  
Model Systems ◽  
Sunflower Seed Oil ◽  
C Terminus ◽  
And Control

At present, most investigations involving the Maillard reaction models have focused on free amino acids (FAAs), whereas the effects of peptides on volatile products are poorly understood. In our study, the formation mechanism of pyrazines, which were detected as characteristic volatiles in sunflower seed oil, from the reaction system of glucose and lysine-containing dipeptides and tripeptides was studied. The effect of the amino acid sequences of the dipeptides and tripeptides on pyrazine formation was further highlighted. Four different dipeptides and six tripeptides were selected. The results showed that the production of pyrazines in the lysine-containing dipeptide models was higher than that in the tripeptide and control models. Compounds 2,5(6)-Dimethylpyrazine and 2,3,5-trimethylpyrazine were the main pyrazine compounds in the dipeptide models. Furthermore, the C- or N-terminal amino acids of lysine-containing dipeptides can exert an important effect on the formation of pyrazines. In dipeptide models with lysine at the C-terminus, the content of total pyrazines followed the order of Arg−Lys > His−Lys; the order of the total pyrazine content was Lys−His > Lys−Arg in dipeptide models with N-terminal lysine. Additionally, for the tripeptide models with different amino acid sequences, more pyrazines and a greater variety of pyrazines were detected in the tripeptide models with N-terminal lysine/arginine than in the tripeptide models with N-terminal histidine. However, the total pyrazine content and the percentage of pyrazines in the total volatiles were similar in the tripeptide models with the same amino acids at the N-terminus. This study clearly illustrates the ability of dipeptides and tripeptides containing lysine, arginine and histidine to form pyrazines, improving volatile formation during sunflower seed oil processing.

scholarly journals Basis for Signaling Specificity Difference between Sos and Ras-GRF Guanine Nucleotide Exchange Factors

2001 ◽  
Vol 276 (50) ◽  
pp. 47248-47256 ◽  
Author(s):  
Xuejun Tian ◽  
Larry A. Feig
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Guanine Nucleotide Exchange Factors ◽  
Amino Acid Sequences ◽  
Guanine Nucleotide ◽  
Nucleotide Exchange ◽  
Ras Proteins ◽  
Signaling Specificity ◽  
Guanine Nucleotide Exchange ◽  
Nucleotide Exchange Factors

Sos and Ras-GRF are two families of guanine nucleotide exchange factors that activate Ras proteins in cells. Sos proteins are ubiquitously expressed and are activated in response to cell-surface tyrosine kinase stimulation. In contrast, Ras-GRF proteins are expressed primarily in central nervous system neurons and are activated by calcium/calmodulin binding and by phosphorylation. Although both Sos1 and Ras-GRF1 activate the Ras proteins Ha-Ras, N-Ras, and Ki-Ras, only Ras-GRF1 also activates the functionally distinct R-Ras GTPase. In this study, we determined which amino acid sequences in these exchange factors and their target GTPases are responsible for this signaling specificity difference. Analysis of chimeras and individual amino acid exchanges between Sos1 and Ras-GRF1 revealed that the critical amino acids reside within an 11-amino acid segment of their catalytic domains between the second and third structurally conserved regions (amino acids (aa) 828–838 in Sos1 and 1057–1067 in Ras-GRF1) of Ras guanine nucleotide exchange factors. In Sos1, this segment is in helix B, which is known to interact with the switch 2 region of Ha-Ras. Interestingly, a similar analysis of Ha-Ras and R-Ras chimeras did not identify the switch 2 region of Ha-Ras as encoding specificity. Instead, we found a more distal protein segment, helix 3 (aa 91–103 in Ha-Ras and 117–129 in R-Ras), which interacts instead primarily with helix K (aa 1002–1016) of Sos1. These findings suggest that specificity derives from the fact that R-Ras-specific amino acids in the region analogous to Ha-Ras helix 3 prevent a functional interaction with Sos1 indirectly, possibly by preventing an appropriate association of its switch 2 region with helix B of Sos1. Although previous studies have shown that helix B of Sos1 and helix 3 of Ha-Ras are involved in promoting nucleotide exchange on Ras proteins, this study highlights the importance of these regions in establishing signaling specificity.

The decapentaplegic gene: a TGF-β homologue controlling pattern formation in Drosophila

Development ◽  
1989 ◽  
Vol 107 (Supplement) ◽  
pp. 65-74 ◽  
Author(s):  
William M. Gelbart
Keyword(s):  
Amino Acid ◽  
Transforming Growth Factor ◽  
Positional Information ◽  
Early Embryo ◽  
Amino Acid Sequences ◽  
Transcript Accumulation ◽  
Ancestral Gene ◽  
Wide Range ◽  
The Family

The type β transforming growth factor (TGF-β) family of secreted factors encompasses a wide range of structurally related proteins that control the state of determination or differentiation in a wide variety of cell types. For all members of the family that have been studied at the protein level, the active moieties arise as dimers of the C-terminal ∼110 amino acid fragment derived from much longer precursor polypeptides. The hallmark of the family is a series of 7 completely conserved cysteine residues in the C-terminus; other conserved amino acid sequences generally cluster in the vicinity of 6 of these 7 cysteines. This report focuses on our current understanding of the genetic structure and developmental role of the decapentaplegic (dpp) gene in Drosophila, the only member of the TGF-β family thus far identified in invertebrates. The dpp polypeptide bears a sufficiently close relationship to two bone morphogenesis proteins (BMP-2A and BMP-2B) identified in mammals (Wozney et al. 1988, Science 242, 1528–1534) to warrant the suggestion that dpp and the BMP-2s are the descendants of a common ancestral gene. The protein-coding information for dpp is contained within a 6 kb DNA segment. An elaborate cis-regulatory apparatus, encompassing a >55 kb DNA segment, has evolved to control expression of the dpp gene, which is required for determination of dorsal ectoderm in the early embryo, for normal distal outgrowth of the adult appendages, and for sundry other developmental events, which are currently less welldefined. Studies of chimeric individuals and observations of transcript accumulation in situ have demonstrated that the dpp gene is expressed along the A/P boundary of the imaginal disks. A possible role of dpp in elaborating positional information in imaginal disk development is discussed.

Genes for low-molecular-weight heat shock proteins of soybeans: sequence analysis of a multigene family

1985 ◽  
Vol 5 (12) ◽  
pp. 3417-3428
Author(s):  
R T Nagao ◽  
E Czarnecka ◽  
W B Gurley ◽  
F Schöffl ◽  
J L Key
Keyword(s):  
Molecular Weight ◽  
Amino Acid ◽  
Heat Shock ◽  
Dna Sequences ◽  
Regulatory Element ◽  
Amino Acid Sequences ◽  
Striking Similarity ◽  
Low Molecular Weight ◽  
Genes Encoding ◽  
Flanking Regions

Soybeans, Glycine max, synthesize a family of low-molecular-weight heat shock (HS) proteins in response to HS. The DNA sequences of two genes encoding 17.5- and 17.6-kilodalton HS proteins were determined. Nuclease S1 mapping of the corresponding mRNA indicated multiple start termini at the 5' end and multiple stop termini at the 3' end. These two genes were compared with two other soybean HS genes of similar size. A comparison among the 5' flanking regions encompassing the presumptive HS promoter of the soybean HS-protein genes demonstrated this region to be extremely homologous. Analysis of the DNA sequences in the 5' flanking regions of the soybean genes with the corresponding regions of Drosophila melanogaster HS-protein genes revealed striking similarity between plants and animals in the presumptive promoter structure of thermoinducible genes. Sequences related to the Drosophila HS consensus regulatory element were found 57 to 62 base pairs 5' to the start of transcription in addition to secondary HS consensus elements located further upstream. Comparative analysis of the deduced amino acid sequences of four soybean HS proteins illustrated that these proteins were greater than 90% homologous. Comparison of the amino acid sequence for soybean HS proteins with other organisms showed much lower homology (less than 20%). Hydropathy profiles for Drosophila, Xenopus, Caenorhabditis elegans, and G. max HS proteins showed a similarity of major hydrophilic and hydrophobic regions, which suggests conservation of functional domains for these proteins among widely dispersed organisms.

Cloning and sequence analysis of complete cDNA of chitin deacetylase from Mucor racemosus

2007 ◽  
Vol 4 (2) ◽  
pp. 167-172 ◽  
Author(s):  
Jiang Xia-Yun ◽  
Zou Shu-Ming ◽  
Zhou Pei-Gen
Keyword(s):  
Amino Acid ◽  
Untranslated Region ◽  
Three Dimensional ◽  
Amino Acid Sequences ◽  
Dimensional Structure ◽  
Functional Domain ◽  
Mucor Racemosus ◽  
Chitin Deacetylase ◽  
Reading Frame ◽  
Rapid Amplification

AbstractA complete chitin deacetylase (CDA) complementary DNA (cDNA) from Mucor racemosus was cloned and sequenced by reverse transcription-polymerase chain reaction (RT-PCR) and rapid amplification cDNA end (RACE) with gene special conserved primers. The cDNA sequence was submitted to GenBank (DQ538514). The complete cDNA with full-length of 1506 bp contained a 67 bp 5′-untranslated region, an open reading frame of 1344 bp and 95 bp 3′-untranslated region including tailing site AATAAA. The gene encoded a sequence of 448 amino acid residues and consisted of core nucleotides encoding a polysaccharide deacetylase domain covering 32% of the entire sequence. The CDA gene shared sequence homology with those of several fungi. The corresponding homology of the deduced amino acid sequences varied from 21 to 69%. Phylogenetic analysis according to the deduced amino acid sequences matched the classical fungi taxonomy. The three-dimensional structure of this protein was predicted. The protein had a whole CDA functional domain and a polysaccharide deacetylase domain.

scholarly journals Aberrant function of the Ras-related protein TC21/R-Ras2 triggers malignant transformation

1994 ◽  
Vol 14 (6) ◽  
pp. 4108-4115
Author(s):  
S M Graham ◽  
A D Cox ◽  
G Drivas ◽  
M G Rush ◽  
P D'Eustachio ◽  
...  
Keyword(s):  
Amino Acid ◽  
Transformed Cells ◽  
Related Protein ◽  
Ras Proteins ◽  
Oncogenic Potential ◽  
Oncogenic Ras ◽  
Ras Genes ◽  
Transforming Activity ◽  
Related Proteins ◽  
Nih 3T3

Although the human Ras proteins are members of a large superfamily of Ras-related proteins, to date, only the proteins encoded by the three mammalian ras genes have been found to possess oncogenic potential. Among the known Ras-related proteins, TC21/R-Ras2 exhibits the most significant amino acid identity (55%) to Ras proteins. We have generated mutant forms of TC21 that possess amino acid substitutions analogous to those that activate Ras oncogenic potential [designated TC21(22V) and TC21(71L)] and compared the biological properties of TC21 with those of Ras proteins in NIH 3T3 and Rat-1 transformation assays. Whereas wild-type TC21 did not show any transforming potential in vitro, both TC21(22V) and TC21(71L) displayed surprisingly potent transforming activities that were comparable to the strong transforming activity of oncogenic Ras proteins. Like Ras-transformed cells, NIH 3T3 cells expressing mutant TC21 proteins formed foci of morphologically transformed cells in monolayer cultures, proliferated in low serum, formed colonies in soft agar, and developed progressive tumors in nude mice. Thus, TC21 is the first Ras-related protein to exhibit potent transforming activity equivalent to that of Ras. Furthermore, mutant TC21 proteins also stimulated constitutive activation of mitogen-activated protein kinases as well as transcriptional activation from Ras-responsive promoter elements (Ets/AP-1 and NF-kappa B). We conclude that aberrant TC21 function may trigger cellular transformation via a signal transduction pathway similar to that of oncogenic Ras and suggest that deregulated TC21 activity may contribute significantly to human oncogenesis.

scholarly journals Aberrant function of the Ras-related protein TC21/R-Ras2 triggers malignant transformation.

1994 ◽  
Vol 14 (6) ◽  
pp. 4108-4115 ◽  
Author(s):  
S M Graham ◽  
A D Cox ◽  
G Drivas ◽  
M G Rush ◽  
P D'Eustachio ◽  
...  
Keyword(s):  
Amino Acid ◽  
Transformed Cells ◽  
Related Protein ◽  
Ras Proteins ◽  
Oncogenic Potential ◽  
Oncogenic Ras ◽  
Ras Genes ◽  
Transforming Activity ◽  
Related Proteins ◽  
Nih 3T3

Although the human Ras proteins are members of a large superfamily of Ras-related proteins, to date, only the proteins encoded by the three mammalian ras genes have been found to possess oncogenic potential. Among the known Ras-related proteins, TC21/R-Ras2 exhibits the most significant amino acid identity (55%) to Ras proteins. We have generated mutant forms of TC21 that possess amino acid substitutions analogous to those that activate Ras oncogenic potential [designated TC21(22V) and TC21(71L)] and compared the biological properties of TC21 with those of Ras proteins in NIH 3T3 and Rat-1 transformation assays. Whereas wild-type TC21 did not show any transforming potential in vitro, both TC21(22V) and TC21(71L) displayed surprisingly potent transforming activities that were comparable to the strong transforming activity of oncogenic Ras proteins. Like Ras-transformed cells, NIH 3T3 cells expressing mutant TC21 proteins formed foci of morphologically transformed cells in monolayer cultures, proliferated in low serum, formed colonies in soft agar, and developed progressive tumors in nude mice. Thus, TC21 is the first Ras-related protein to exhibit potent transforming activity equivalent to that of Ras. Furthermore, mutant TC21 proteins also stimulated constitutive activation of mitogen-activated protein kinases as well as transcriptional activation from Ras-responsive promoter elements (Ets/AP-1 and NF-kappa B). We conclude that aberrant TC21 function may trigger cellular transformation via a signal transduction pathway similar to that of oncogenic Ras and suggest that deregulated TC21 activity may contribute significantly to human oncogenesis.

scholarly journals The CFTR-derived peptides as a model of sequence-specific protein aggregation

2007 ◽  
Vol 12 (3) ◽  
Author(s):  
Daniel Bąk ◽  
Garry Cutting ◽  
Michał Milewski
Keyword(s):  
Amino Acid ◽  
Protein Aggregation ◽  
Mammalian Cells ◽  
Specific Protein ◽  
Amino Acid Sequences ◽  
Model Systems ◽  
Aggregation Pattern ◽  
C Terminus ◽  
Crucial Component ◽  
Modified Peptides

AbstractProtein aggregation is a hallmark of a growing group of pathologies known as conformational diseases. Although many native or mutated proteins are able to form aggregates, the exact amino acid sequences involved in the process of aggregation are known only in a few cases. Hence, there is a need for different model systems to expand our knowledge in this area. The so-called ag region was previously found to cause the aggregation of the C-terminal fragment of the cystic fibrosis transmembrane conductance regulator (CFTR). To investigate whether this specific amino acid sequence is able to induce protein aggregation irrespective of the amino acid context, we altered its position within the CFTR-derived C-terminal peptide and analyzed the localization of such modified peptides in transfected mammalian cells. Insertion of the ag region into a different amino acid background affected not only the overall level of intracellular protein aggregation, but also the morphology and subcellular localization of aggregates, suggesting that sequences other than the ag region can substantially influence the peptide’s behavior. Also, the introduction of a short dipeptide (His-Arg) motif, a crucial component of the ag region, into different locations within the C-terminus of CFTR lead to changes in the aggregation pattern that were less striking, although still statistically significant. Thus, our results indicate that even subtle alterations within the aggregating peptide can affect many different aspects of the aggregation process.

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