c-Cbl and Cbl-b E3 ubiquitin ligases are abundantly expressed in hemopoietic cells where they negatively regulate the activity and levels of many cell surface receptors and associated signaling molecules. By comparing bone marrow-derived mast cells from c-Cbl and Cbl-b-deficient mice it has recently been shown that Cbl-b is the dominant family member for negatively regulating signaling response...

Recent reports indicate that oxidized cobalamin, Cbl(III), can interfere with the biological effects of nitric oxide (NO) on vascular and visceral smooth muscle and in other systems. In attempting to elucidate the mechanism of these effects of Cbl(III), we reported that a Cbl(III)NO complex could be detected by electron paramagnetic resonance (EPR) spectroscopy, but not by ultraviolet/visible s...

OBJECTIVE c-Cbl plays an important role in whole-body fuel homeostasis by regulating insulin action. In the present study, we examined the role of Cbl-b, another member of the Cbl family, in insulin action. RESEARCH DESIGN AND METHODS C57BL/6 (Cbl-b(+/+)) or Cbl-b-deficient (Cbl-b(-/-)) mice were subjected to insulin and glucose tolerance tests and a hyperinsulinemic-euglycemic clamp test. In...

The Cbl ubiquitin ligase has emerged as a negative regulator of receptor and non-receptor tyrosine kinases. Cbl is known to associate with the proto-oncogene product Vav, a hematopoietic-restricted Rac guanine nucleotide exchange factor, but the consequences of this interaction remain to be elucidated. Using immortalized T cell lines from Cbl(+/+) and Cbl(-/-) mice, and transfection analyses in...

There is accumulating evidence for the existence of HNO in biological systems. Compared with NO (˙NO), much less is known about the chemical and biochemical reactivity of HNO. Kinetic and mechanistic studies have been carried out on the reaction between the vitamin B12-derived radical complex cob(II)alamin (Cbl(II)˙, Cbl(II)) with the widely used HNO donor Piloty's acid (PA). A stoichiometry of...

Cobalamin (Cbl) transport across the outer membrane of cells of Escherichia coli consists of high affinity Cbl binding to the btuB protein of the Cbl receptor, followed by the proton motive force- and tonB-dependent release of the Cbl into the periplasmic space. During a search for experimental conditions that would mimic this release in vitro with isolated cell envelope particles, we found tha...

Solomon1 claims that many patients with clinical features suggestive of cobalamin (Cbl) deficiency who have normal serum Cbl, methylmalonic acid (MMA), and homocysteine (HCys) levels may respond to Cbl therapy, while many patients with low serum Cbl, high serum MMA, or high serum HCys levels may fail to respond to Cbl therapy. He concludes that these tests are unreliable for the diagnosis of Cb...

Paper reviews recent laboratory and numerical model studies of passive gaseous tracer dispersion in the atmospheric convective boundary layer (CBL) with surface and elevated wind shears. Atmospheric measurement data used for validation of these two model techniques are briefly discussed as well. A historical overview is given of laboratory studies of dispersion in the atmospheric CBL. Model stu...

Solomon1 claims that many patients with clinical features suggestive of cobalamin (Cbl) deficiency who have normal serum Cbl, methylmalonic acid (MMA), and homocysteine (HCys) levels may respond to Cbl therapy, while many patients with low serum Cbl, high serum MMA, or high serum HCys levels may fail to respond to Cbl therapy. He concludes that these tests are unreliable for the diagnosis of Cb...

We previously reported the potential involvement of casitas B-cell lymphoma-b (Cbl-b) in aging-related murine insulin resistance. Because obesity also induces macrophage recruitment into adipose tissue, we elucidated here the role of Cbl-b in obesity-related insulin resistance. Cbl-b(+/+) and Cbl-b(-/-) mice were fed a high-fat diet (HFD) and then examined for obesity-related changes in insulin...