Protein modification by SUMO (small ubiquitin-related modifier) has emerged as an essential regulatory mechanism in eukaryotes. Even though the molecular mechanisms of SUMO conjugation/deconjugation are conserved, the number of SUMO machinery components and their degree of conservation are specific to each organism. In the present paper, we show data contributing to the notion that the four exp...

Parts of 5' non-coding (5' NC) and of E1 envelope regions of the hepatitis C virus (HCV) genome were amplified from sera of 26 Brazilian anti-HCV antibody-positive patients using the reverse transcription-polymerase chain reaction (RT-PCR). Fourteen samples were PCR positive with primers from the 5' NC region and 8 of them were also positive with primers from the E1 region. A genomic segment of...

In vitro DNA binding results from a series of E1 proteins containing amino-terminal or carboxy-terminal truncations indicated that sequences between amino acids 121 and 284 were critical for origin binding. Additional binding experiments with E1 proteins containing internal, in-frame insertions or deletions confirmed the importance of the region defined by truncated E1 proteins and also demonst...

Endothelial 1 (E1) is identified as an endothelial cell secreted factor that stimulates collagen gel contraction by fibroblasts. This identification is based on (a) co-localization of stimulatory activity in endothelial cell conditioned media with synthetic E1 in reversed phase analysis; (b) removal of the activity from conditioned media with antiserum directed against E1; and (c) the activity ...

Cyclin E1 regulates the initiation of S-phase in cellular division. However, in many cancers, cyclin E1 is aberrantly overexpressed and this molecular phenotype correlates with increased tumor aggressiveness and poor patient survival. The molecular cause(s) of cyclin E1 abnormalities in cancers is poorly understood. Here, we show that cyclin E1 overexpression in cancer is promoted by dysregulat...

The E1 helicase from BPV and HPV16 interacts with Ubc9 to facilitate viral genome replication. We report that HPV11 E1 also interacts with Ubc9 in vitro and in the yeast two-hybrid system. Residues in E1 involved in oligomerization (353-435) were sufficient for binding to Ubc9 in vitro, but the origin-binding and ATPase domains were additionally required in yeast. Nuclear accumulation of BPV E1...

Papillomaviral infection causes both benign and malignant lesions and is a necessary cause of cervical carcinoma. Replication of this virus requires the replication initiation proteins E1 and E2, which bind cooperatively at the origin of replication (ori) as an (E1)2-(E2)2-DNA complex. This is a precursor to larger E1 complexes that distort and unwind the ori. We present the crystal structure o...

We prove a general result on the factorization of matrix-valued analytic functions. We deduce that if (E0, E1) and (F0, F1) are interpolation pairs with dense intersections, then under some conditions on the spaces E0, E1, F0 and F1, we have [E0⊗̂F0, E1⊗̂F1]θ = [E0, E1]θ⊗̂[F0, F1]θ, 0 < θ < 1. We find also conditions on the spaces E0, E1, F0 and F1 , so that the following holds [E0 ∨ ⊗F0, E1 ∨ ⊗F1...

The behavior of natural estrogens was examined by separately spiking 17β-estradiol (E2) and estrone (E1) into semicontinuous activated sludge reactors operated under aerobic, anaerobic and sequential anaerobic/aerobic conditions. Under aerobic and anaerobic conditions, E1 was formed from E2. The conversion of E1 to E2 was maximum conversion of E2 to E1 was higher than t E1 to E2. Overall, the d...