The expression of the catalytic subunit (hTERT) represents the limiting factor for telomerase activity. Previously, we detected a transcriptional repressor effect of the proximal exonic region (first two exons) of the hTERT gene. To better understand the mechanism involved and to identify a potential repressor, we further characterized this region. ... More
Heparan sulfate degradation products can associate with oxidized proteins and proteasomes.
AuthorsMani K, Cheng F, Fransson LA,
JournalJ Biol Chem
PubMed ID17540770
The S-nitrosylated proteoglycan glypican-1 recycles via endosomes where its heparan sulfate chains are degraded into anhydromannose-containing saccharides by NO-catalyzed deaminative cleavage. Because heparan sulfate chains can be associated with intracellular protein aggregates, glypican-1 autoprocessing may be involved in the clearance of misfolded recycling proteins. Here we have arrested and then ... More
The heme activator protein Hap1 represses transcription by a heme-independent mechanism in Saccharomyces cerevisiae.
AuthorsHon T, Lee HC, Hu Z, Iyer VR, Zhang L,
JournalGenetics
PubMed ID15654089
The yeast heme activator protein Hap1 binds to DNA and activates transcription of genes encoding functions required for respiration and for controlling oxidative damage, in response to heme. Hap1 contains a DNA-binding domain with a C6 zinc cluster motif, a coiled-coil dimerization element, typical of the members of the yeast ... More
The luminal Vps10p domain of sortilin plays the predominant role in targeting to insulin-responsive Glut4-containing vesicles.
AuthorsShi J, Kandror KV,
JournalJ Biol Chem
PubMed ID17220298
In fat and skeletal muscle cells, insulin-responsive vesicles, or IRVs, deliver glucose transporter Glut4 and several associated proteins to the plasma membrane in response to hormonal stimulation. Although the protein composition of the IRVs is well studied, the mechanism of their formation is unknown. It is believed, however, that the ... More