Nuclear localization of vertebrate cyclin A correlates with its ability to form complexes with cdk catalytic subunits.

Cyclins control the activities of cyclin-dependent protein kinases (cdks) and hence play a key role in cell cycle regulation. While B-type cyclins associate with p34cdc2 to trigger entry into mitosis, progression through S phase requires cyclin A, presumably in association with p33cdk2. Vertebrate A- and B-type cyclins display strikingly distinct subcellular localizations, but the mechanisms underlying these differential distributions are unknown.

Casein kinase II is a predominantly nuclear enzyme.

Casein kinase II (CK II) has been implicated in regulating multiple processes related to cell growth, proliferation, and differentiation. To better understand the function(s) and regulation of this ubiquitous kinase, it is important to know its subcellular distribution. However, this issue has been the subject of contradictory reports.

Casein kinase II. cDNA sequences, developmental expression, and tissue distribution of mRNAs for alpha, alpha', and beta subunits of the chicken enzyme.

We report the complete primary structures, as deduced from cloned cDNAs, of two catalytic (alpha and alpha') and one beta subunit of chicken casein kinase II. The alpha and alpha' subunits are closely related to each other but differ in their carboxyl termini; moreover, minor differences are distributed throughout the entire lengths of the two proteins, indicating that they are derived from separate genes. Comparison of the chicken protein sequences with those of their mammalian homologs reveals a high degree of evolutionary conservation of all three subunits.

Structure and developmental expression of chicken nucleolin and NO38: coordinate expression of two abundant non-ribosomal nucleolar proteins.

We report the complete primary structures of two major chicken non-ribosomal nucleolar proteins known as nucleolin/C23 and NO38/B23, respectively. By comparison with homologous proteins from other species, this sequence information contributes to the identification of evolutionarily conserved motifs that may be relevant to the function and subcellular distribution of the two proteins. Using cDNA probes and monoclonal antibodies, we have also studied the expression of nucleolin and NO38 in the course of chicken embryogenesis.

Caffeine-induced diuresis and atrial natriuretic peptides.

After a single-blind, randomized, cross-over protocol using decaffeinated coffee in a control experiment, the effect of an oral 250-mg caffeine dose on plasma immunoreactive atrial natriuretic peptide (ANF) was assessed in eight healthy students who had been on a methylxanthine-free diet for 1 week. One to 2 h after caffeine ingestion, both systolic blood pressure (SBP) and diastolic BP (DBP) increased by 12 mm Hg while heart rate (HR) also tended to increase. An increase in diuresis and in urinary sodium, potassium, and osmol excretion was observed within 1 h.