Ubiquitin conjugation provides a crucial signaling role in hundreds of cellular pathways; however, a structural understanding of ubiquitinated substrates is lacking. One important substrate is monoubiquitinated PCNA (PCNA-Ub), which signals for recruitment of damage-tolerant polymerases in the translesion synthesis (TLS) pathway of DNA damage avoidance. We use a novel and efficient enzymatic me...

PCNA (proliferating-cell nuclear antigen) is a ring-shaped protein that encircles duplex DNA and plays an essential role in many DNA metabolic processes. The PCNA protein interacts with a large number of cellular factors and modulates their enzymatic activities. In the present paper, we summarize the structures, functions and interactions of the archaeal PCNA proteins.

Nuclear proteins contain a signal, termed the nuclear transport signal, that specifies their selective transport into the nucleus. Previously we reported that antibodies to Asp-Asp-Asp-Glu-Asp (DDDED) inhibited nuclear transport of nuclear proteins in vivo. We therefore tried to detect a cellular receptor of nuclear transport signals as a protein that reacted with both anti-DDDED antibody and n...

Systemic lupus erythematosus (SLE) is the most common autoimmune disease. It is characterized by the presence of hundreds of autoantibodies against many organs and tissues, including the presence of a large number of autoantibodies, which are specific to self-antigens mainly of nuclear origin such as Smith antigen, double-stranded DNA (dsDNA), anti-Sjögren’s syndrome-related antigen A and B (SS...

Objective: Parathyroid adenomas are the most common cause of primary hyperparathyroidism. Biological studies have shown that parathyroid adenomas are monoclonal proliferations. Up to date, five cell types have been identified in normal parathyroid tissues; chief cells, vacuolated chief cells, dark chief cells, oxyphil cells and transitional oxyphil cells. Most parathyroid adenomas are predomina...

mAbs were generated against HeLa nuclear matrix proteins and one, HIB2, which selectively stained mitotic cells, was selected for further study. Western blot analysis showed H1B2 antibody detected a protein of 240 kD in the nuclear matrix fractions. The H1B2 antigen was completely masked in immunofluorescently stained interphase cells. However, removing chromatin with DNase I digestion and 0.25...