The F-box protein superfamily represents one of the largest families in the plant kingdom. F-box proteins phylogenetically organize into numerous subfamilies characterized by their carboxyl (C)-terminal protein-protein interaction domain. Among the largest F-box protein subfamilies in plant genomes are those with C-terminal kelch repeats. In this study, we analyzed the phylogeny and evolution o...

A T-lymphocyte-specific enhancer located 13 kb upstream of the murine CD4 gene was recently shown to be required for the developmentally regulated expression of CD4. We have previously identified three nuclear protein binding sites in this enhancer; one of these sites, CD4-3, is essential for expression and contains two E-box core motifs (CANNTG) adjacent to each other in the sequence TAACAGGTG...

ECS (Elongin BC-Cul2/Cul5-SOCS-box protein) ubiquitin ligases recruit substrates to E2 ubiquitin-conjugating enzymes through a SOCS-box protein substrate receptor, an Elongin BC adaptor and a cullin (Cul2 or Cul5) scaffold which interacts with the RING protein. In vitro studies have shown that the conserved amino acid sequence of the cullin box in SOCS-box proteins is required for complex forma...

Y-box proteins belong to the cold shock domain family of proteins that are known to be involved in both transcriptional and translational control. Here, we give a brief overview of the structure, regulation and physiological functions of the Y-box proteins. This is followed by examining the role of Y-box protein 1 (YB-1), the most extensively studied of the Y-box protein in tumorigenesis, and i...

The Schizosaccharomyces pombe mfm1 gene is expressed in an M cell-specific fashion. This regulation requires two HMG-box proteins: the ubiquitous Ste11 transcription factor and the M cell-controlling protein Mat1-Mc. Here we report that the mfm1 promoter contains a single, weak Stell-binding site (a so-called TR-box) that can confer M-specificity on a heterologous promoter when present in eight...

Transcriptional regulation is pivotal for development and differentiation of organisms. Transcription of eukaryotic protein-coding genes by RNA polymerase II (Pol II) initiates at the core promoter. Core promoters, which encompass the transcription start site, may contain functional core promoter elements, such as the TATA box, initiator, TCT and downstream core promoter element. TRF2 (TATA-box...

Cullins assemble the largest family of ubiquitin ligases by binding with ROC1 and various substrate receptors. CUL4 function is linked with many cellular processes, but its substrate-recruiting mechanism remains elusive. We identified a protein motif, the DWD box (DDB1-binding WD40 protein), and demonstrated the binding of 15 DWD proteins with DDB1-CUL4A. We provide evidence supporting the crit...