• Journal of Mushroom
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• v.9 no.1
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• pp.3-16
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• 2011

In the bipolar basidiomycete Pholiota nameko, a pair of homeodomain protein genes located at the A mating-type locus regulates mating compatibility. In the present study, we used a DNA-mediated transformation system in P. nameko to investigate the homeodomain proteins that control the clamp formation. When a single homeodomain protein gene (A3-hox1 or A3-hox2) from the A3 monokaryon strain was introduced into the A4 monokaryon strain, the transformants produced many pseudo-clamps but very few clamps. When two homeodomain protein genes (A3-hox1 and A3-hox2) were transformed either separately or together into the A4 monokaryon, the ratio of clamps to the clamp-like cells in the transformants was significantly increased to approximately 50%. We, therefore, concluded that the gene dosage of homeodomain protein genes is important for clamp formation. When the sip promoter was connected to the coding region of A3-hox1 and A3-hox2 and the fused fragments were introduced into NGW19-6 (A4), the transformants achieved more than 85% clamp formation and exhibited two nuclei per cell, similar to the dikaryon (NGW12-163 ${\times}$ NGW19-6). The results of real-time RT-PCR confirmed that sip promoter activity is greater than that of the native promoter of homeodomain protein genes in P. nameko. So, we concluded that nearly 100% clamp formation requires high expression levels of homeodomain protein genes and that altered expression of the A mating-type genes alone is sufficient to drive true clamp formation.

• BMB Reports
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• v.34 no.1
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• pp.1-7
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• 2001

Structural and physical properties of type wild type and various selected mutants of the vnd/NK-2 homeodomain, the protein product of the homeobox, and the implication in genetic disease are reviewed. The structure, dynamics and thermodynamics have been Investigated by NMR and by calorimetry. The interactions responsible for the nucleotide sequence-specific binding of the homeodomain to its consensus DNA binding site have been identified. There is a strong correlation between significant structural alterations within the homeodomain or its DNA complex and the appearance of genetic disease. Mutations in positions known to be important in genetic disease have been examined carefully For example, mutation of position 52 of vnd/NK-2 results in a significant structural modification and mutation of position 54 alters the DNA binding specificity and amity The $^{15}N$ relaxation behavior and heteronuclear Overhauser effect data was used to characterize and describe the protein backbone dynamics. These studies were carried out on the wild type and the double mutant proteins both in the free and in the DNA bound states. Finally, the thermodynamic properties associated with DNA binding are described for the vnd/NK-2 homeodomain. These thermodynamic measurements reinforce the hypothesis that water structure around a protein and around DNA significantly contribute to the protein-DNA binding behavior. The results, taken together, demonstrate that structure and dynamic studies of proteins combined with thermodynamic measurements provide a significantly more complete picture of the solution behavior than the individual studies.

• BMB Reports
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• v.37 no.3
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• pp.320-334
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• 2004

StMBF1 (Solanum tuberosum multiprotein bridging factor 1) is a plant member of the MBF1 family of transcriptional co-activators. In an attempt to understand the role of StMBF1, we analyzed its interaction with plant transcription factors of the homeodomain-leucine zipper (Hd-Zip) family, a group of proteins with a typical leucine zipper motif adjacent to a homeodomain. StMBF1 is able to interact in vitro with the Hd-Zip protein Hahb-4 both in the presence and absence of DNA. Upon binding, StMBF1 increases the DNA binding affinity of Hahb-4, and of another plant homeodomain containing protein from the GL2/Hd-Zip IV family, HAHR-1. The biological role of interactions is discussed in this paper.

• Journal of Life Science
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• v.12 no.2
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• pp.173-181
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• 2002

This study was conducted to do the comparative analysis of mating type locus controlling the direct formation of fruiting body in Schizophyllum commune which is indigenous to North America with that of other identified mating locus. The 3120 bp Y-region nucleotide of A $\alpha$ 3 mating locus activating a developmental pathway in S. commune was determined, and appeared to have about 96% homology to S. commune 1-71 $A\alpha$3 allele indigenous to South America, showing strongly a conservative feature. This nucleotide analysis also showed above 96% homology highly in the seven presumed exons, and about 97% in the acidic rich region (AR), about 99% in homeodomain (H7), about 97% in the basic rich region (BR), about 95% in the serine rich region (Ser) respectively. In the comparative analysis to the translated polypeptide sequence, S. commune A $\alpha$ 3 mating locus containing Y-region also showed about 97% homology to the region of S. commune indigenous to North America, but the identity ratio to Y1 including Y4, Y5, Y6 different allele types was declined to about 41~49%. In the analysis of functional loci controlling mating activity, it is assumed to have a highly conservative feature showing about 98% homology in homeodomain polypeptide. Especially, it is notable that the homology ratio of above 85% in homeodomain motif between mating type alleles was higher than in the AR, BR, Ser showing about 10~50% homology.

• BMB Reports
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• v.43 no.6
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• pp.407-412
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• 2010

Homeodomain (HD) is a highly conserved DNA-binding domain composed of helix-turn-helix motif. Drosophila Vnd (Ventral nervous system defective) containing HD acts as a regulator to either enhance or suppress gene expression upon binding to its target sequence. In this study, kinetic analysis of Vnd binding to DNA was performed. The result demonstrates that DNA-binding affinity of the recombinant protein containing HD and NK2-specific domain (NK2-SD) was higher than that of the full-length Vnd. To access whether phosphorylation sites within HD and NK2-SD affect the interaction of the protein with the target sequence, alanine substitutions were introduced. The result shows that S631A mutation within NK2-SD does not contribute significantly to the DNA-binding affinity. However, S571A and T600A mutations within HD showed lower affinity for DNA binding. In addition, DNA-binding analysis using embryonic nuclear protein also demonstrates that Vnd interacts with other nuclear proteins, suggesting the existence of Vnd as a complex.

• BMB Reports
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• v.47 no.2
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• pp.92-97
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• 2014

We have examined the effect of bithorax complex genes on the expression of castor gene. During the embryonic stages 12-15, both Ultrabithorax and abdominal-A regulated the castor gene expression negatively, whereas Abdominal-B showed a positive correlation with the castor gene expression according to real-time PCR. To investigate whether ABD-B protein directly interacts with the castor gene, electrophoretic mobility shift assays were performed using the recombinant ABD-B homeodomain and oligonucleotides, which are located within the region 10 kb upstream of the castor gene. The results show that ABD-B protein directly binds to the castor gene specifically. ABD-B binds more strongly to oligonucleotides containing two 5'-TTAT-3' canonical core motifs than the probe containing the 5'-TTAC-3' motif. In addition, the sequences flanking the core motif are also involved in the protein-DNA interaction. The results demonstrate the importance of HD for direct binding to target sequences to regulate the expression level of the target genes.

• 한국균학회소식:학술대회논문집
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• 2014.10a
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• pp.42-42
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• 2014

Mating of tetrapolar mushrooms is regulated by to chromosomal loci, A and B. A locus contains A gene that expresses a homeodomain protein whereas B locus contains multiple pheromones and receptor genes. In order to characterize the mating loci in Korean cultivated strains of Lentinula edodes, one hundred monokaryotic myclelia were isolated from the basidiospores of cultivated strains, including Cham-A-Ram, Sanjo701, and Sanjo707. Both mating loci were amplified using primer sets targeting conserved sequence regions for homeodomain (HD), pheromone, and receptor genes. Subsequent sequence analysis revealed that the Korean strains contained significant variations in the homeodomain of A locus, even within the same A1 or A2 mating type. Similarly, B locus was also highly diversified in the sequences of pheromones and receptors as well as gene organization. These results enabled us to design mating type-specific probes which can distinguish mating type of each strain. The specificity was confirmed by between intra- and inter-strain mating experiment.

• Journal of Life Science
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• v.21 no.2
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• pp.194-201
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• 2011

Caudal-related homeodomain proteins play critical roles in intestine development and maintenance from Drosophila to humans. The loss or reduction of CDX1 and CDX2 are known to be associated with colon cancers. It has been well known that colorectal carcinogenesis is associated with serious oxidative stress and that catalase is decreased in colon carcinomas. However, the underlying molecular mechanisms remain elusive. Here, we report that Caudal-related homeodomain proteins positively regulate catalase expression in both Drosophila and humans. We found that Drosophila caudal heterozygotes have a decreased catalase expression and increased ROS generation in the hindgut, and that the overexpression of Caudal increases catalase promoter activity and catalase mRNA levels. We also found that CDX1 and CDX2 up-regulate catalase promoter activity and protein levels in HCT116 cells - human colorectal carcinoma cell lines. The level of catalase protein in several colorectal carcinoma cell lines was associated with CDX1 expression. These results suggest that CDX1 and CDX2 may be involved in intestinal homeostasis and tumorigenesis via regulation of catalase expression.

• The Zoological Society Korea : Newsletter
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• v.12 no.2
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• pp.121.1-121
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• 1995

No Abstract, See Full Text

• Proceedings of the Zoological Society Korea Conference
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• 1995.10b
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• pp.334.1-334
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• 1995