p23, a novel mammalian nucleic acid-binding protein with homology to the yeast ribosomal protein YL43.

When separating perchloric acid-soluble proteins from cell cultures and tissues by chromatography on single stranded DNA agarose columns, a novel mammalian protein with extreme affinity for DNA was isolated. Cellular localization, amino acid composition and the N-terminal sequence suggest that the protein is a ribosomal protein with extensive sequence homology to the ribosomal protein, YL43, from Saccharomyces cerevisiae.

A common deletion in the uridine diphosphate glucuronyltransferase (UGT) 2B17 gene is a strong determinant of androgen excretion in healthy pubertal boys.

BACKGROUND: Testosterone (T) is excreted in urine as water-soluble glucuronidated and sulfated conjugates. The ability to glucuronidate T and other steroids depends on a number of different glucuronidases (UGT) of which UGT2B17 is essential. The aim of the study was to evaluate the influence of UGT2B17 genotypes on urinary excretion of androgen metabolites in pubertal boys. STUDY DESIGN: A clinical study of 116 healthy boys aged 8-19 yr. UGT2B17 genotyping was performed using quantitative PCR. Serum FSH, LH, T, estradiol (E2), and SHBG were analyzed by immunoassays, and urinary levels of androgen metabolites were quantitated by gas chromatography/mass spectrometry in all subjects. RESULTS: Ten of 116 subjects (9%) presented with a homozygote deletion of the UGT2B17 gene (del/del), whereas 52 and 54 boys were hetero- and homozygous carriers of the UGT2B17 gene (del/ins and ins/ins), respectively. None of the reproductive hormones were affected by UGT2B17 genotype. In all subjects, mean urinary T/epitestosterone ratio was 1.56 [1.14 (SD); 0.1-6.9 (range)] and unaffected by age or pubertal stage. Subjects with homozygous deletions of UGT2B17 had significantly lower urinary levels of T and 5alpha- and 5beta-androstanediol. Mean urinary T/epitestosterone was significantly reduced in del/del subjects [0.29 (0.30); 0.1-1.0 (range), P < 0.0001]. CONCLUSION: In pubertal boys, a common homozygous deletion in the UGT2B17 gene strongly affected urinary excretion pattern of androgen metabolites but did not influence circulating androgen levels.

The phosphate groups of the high mobility group like protein P1 strengthens its affinity for DNA.

PCA soluble proteins isolated from rat liver and proliferating HeLa interphase cells were subjected to chromatography on columns containing immobilized s.s and d.s. DNA. P1 from rat liver was eluted from s.s. and d.s. DNA between 0.20 and 0.45 M NaCl, while dephosphorylated P1 was not retained by s.s. and d.s. DNA columns at 0.25 M, suggesting that phosphate groups enhance the affinity of P1 for DNA. P1 from proliferating HeLa interphase cells exhibit increased affinity for d.s. as well as s.s. DNA when compared to rat liver P1. The higher extent of phosphorylation in proliferating cells supports the finding that phosphate enhances rather than reduces the affinity of P1 for DNA.