When cells enter mitosis, the anaphase-promoting complex/cyclosome (APC/C) is activated by phosphorylation and binding of Cdc20. The RXXL destruction box (D-box) of cyclin B1 only binds Cdc20 after release of the spindle checkpoint in metaphase, initiating cyclin B1 ubiquitination upon chromosome bi-orientation. However, we found that cyclin B1, through Cdk1 and Cks, is targeted to the phosphor...

The in vitro polymerization and tissue-specific expression patterns of the four essential intermediate filament (IF) proteins (A1, A2, A3, B1) and the non-essential IF protein A4 were analyzed. Recombinant B1, used as a probe in blot overlay assays of the 11 Caenorhabditis elegans IF proteins, reacted strongly with proteins A1 to A4, indicating a heterotypic interaction. Obligate heteropolymeri...

Various chymotrypsin inhibitors occur in the hemolymph of silkworm larvae. Interaction of chymotrypsin inhibitor b1 (CI-b1) with Escherichia coli was examined from the viewpoint of action against invading bacteria. Injection of dead E. coli cells into larva reduced the CI-b1 content of the hemolymph, suggesting in vivo binding of CI-b1 to the outer membrane of the cell. Results from incubation ...

Lamins B1 and B2 (B-type lamins) have very similar sequences and are expressed ubiquitously. In addition, both Lmnb1- and Lmnb2-deficient mice die soon after birth with neuronal layering abnormalities in the cerebral cortex, a consequence of defective neuronal migration. The similarities in amino acid sequences, expression patterns, and knockout phenotypes raise the question of whether the two ...

The cellular and molecular mechanisms governing bradykinin B1 and B2 receptor expression and function are poorly understood. We investigated the regulation of both B1 and B2 receptors in human embryonic lung fibroblasts (HEL 299) by the proinflammatory cytokines tumor necrosis factor alpha (TNF-alpha) and interleukin 1beta (IL-1beta). TNF-alpha and IL-1beta both induced a rapid and transient in...

Introduction: A common approach to B1+ characterization of TX-arrays involves transmitting with different combinations of array elements and decoding the combined field maps to obtain single channel field maps [1,2]. This leads to an improved SNR behavior compared to the straightforward approach of B1+ characterization where only one array element with limited spatial TX-sensitivity in the FOV ...

Introduction: It has been shown that the B1 inhomogeneities in high field systems (e.g.7T) can severely compromise image quality. B1 inhomogeneities are still significant at 3T, but generally do not destroy the ability to image. However, the variations in flip angle (and hence contrast) across the field of excitation can still cause significant problems, particularly with applications where abs...

τ∗ = inf { t∗ ≤ t ≤ T | b1(t) ≤ S t −B t ≤ b2(t) } where t∗ ∈ [0, T ) and the functions t 7→ b1(t) and t 7→ b2(t) are continuous on [t∗, T ] with b1(T )=0 and b2(T )=1/2μ . If μ > 0 then b1 is decreasing and b2 is increasing on [t∗, T ] with b1(t∗) = b2(t∗) when t∗ 6= 0 . Using local time-space calculus we derive a coupled system of nonlinear Volterra integral equations of the second kind and s...

Cyclin B1-CDK1 activity is essential for mitotic entry, but questions remain regarding how the activity of this kinase is spatially regulated. Previous studies showed that the cyclin B1 subunit localizes to several compartments of a mitotic cell, including the centrosomes, mitotic spindle, kinetochores and chromosomes via distinct sequence elements. Mitotic chromosome association occurs through...