MYB family genes are widely distributed in plants and comprise one of the largest transcription factors involved in various developmental processes and defense responses of plants. To date, few MYB genes and little expression profiling have been reported for citrus. Here, we describe and classify 177 members of the sweet orange MYB gene (CsMYB) family in terms of their genomic gene structures a...

In the present study, we demonstrated the cell cycle periodicity of Erbin expression with the maximal expression of Erbin in G2/M phase. A significant increase in Erbin promoter activity was observed in G2/M phase-synchronized cells. Sequence analysis revealed a c-Myb site in the core promoter region of Erbin. Mutagenesis of c-Myb consensus sequences abrogated the increased Erbin promoter activ...

Most E2F-binding sites repress transcription through the recruitment of Retinoblastoma (RB) family members until the end of the G1 cell-cycle phase. Although the MYB promoter contains an E2F-binding site, its transcription is activated shortly after the exit from quiescence, before RB family members inactivation, by unknown mechanisms. We had previously uncovered a nuclear factor distinct from ...

In hematopoietic cell development, the c-myb transcription factor plays an important role. c-myb mRNA is expressed at high levels in immature proliferating cells and in leukemic cells. We have investigated the regulatory role of Myb protein binding to the human c-myb promoter. Three Myb binding sites have been described at approximately 600 bp upstream of the cap site. By transient transfection...

The MYB family of proteins is large, functionally diverse and represented in all eukaryotes. Most MYB proteins function as transcription factors with varying numbers of MYB domain repeats conferring their ability to bind DNA. In plants, the MYB family has selectively expanded, particularly through the large family of R2R3-MYB. Members of this family function in a variety of plant-specific proce...

Myb family proteins are ubiquitously expressed transcription factors. In mammalian cells, they play a critical role in regulating the G(1)/S cell cycle transition but their role in regulating other cell cycle checkpoints is incompletely defined. Herein, we report experiments which demonstrate that c-Myb upregulates cyclin B1 expression in normal and malignant human hematopoietic cells. As a res...

Using the yeast two-hybrid system, the transcription factor ATBF1 was identified as v-Myb- and c-Myb-binding protein. Deletion mutagenesis revealed amino acids 2484-2520 in human ATBF1 and 279-300 in v-Myb as regions required for in vitro binding of both proteins. Further experiments identified leucines Leu325 and Leu332 of the Myb leucine zipper motif as additional amino acid residues importan...

The v-Myb protein encoded by avian myeloblastosis virus causes oncogenic transformation of monoblastic cells committed to the monocyte/macrophage lineage. v-Myb is a doubly truncated form of its normal cellular counterpart, c-Myb. In addition to its N- and C-terminal deletions, v-Myb contains a number of amino acid substitutions relative to c-Myb. We have previously shown that neither overexpre...

A-myb is a member of the myb family of transcription factors, which regulates proliferation, differentiation, and apoptosis of hematopoietic cells. A-Myb expression is normally restricted to the proliferating B-cell centroblasts and transgenic mice overexpressing A-myb displayed enhanced hyperplasia of the lymph nodes. Because A-Myb is highly expressed in several subtypes of human B-cell neopla...

The c-Myb transcription factor is crucial during definitive hematopoiesis. However, the embryonic lethality of Myb traditional null mutations has precluded analysis of c-Myb function in lymphocytes. Using tissue-specific inactivation at the Myb locus, we demonstrate that loss of Myb causes a partial block during B cell development at the pro-B to pre-B cell transition, resulting in greatly decr...