Distinctive roles of PHAP proteins and prothymosin-alpha in a death regulatory pathway

A small molecule, alpha-(trichloromethyl)-4-pyridineethanol (PETCM), was identified by high-throughput screening as an activator of caspase-3 in extracts of a panel of cancer cells. PETCM was used in combination with biochemical fractionation to identify a pathway that regulates mitochondria-initiated caspase activation. This pathway consists of tumor suppressor putative HLA-DR-associated proteins (PHAP) and oncoprotein prothymosin-alpha (ProT). PHAP proteins promoted caspase-9 activation after apoptosome formation, whereas ProT negatively regulated caspase-9 activation by inhibiting apoptosome formation. PETCM relieved ProT inhibition and allowed apoptosome formation at a physiological concentration of deoxyadenosine triphosphate. Elimination of ProT expression by RNA interference sensitized cells to ultraviolet irradiation-induced apoptosis and negated the requirement of PETCM for caspase activation. Thus, this chemical-biological combinatory approach has revealed the regulatory roles of oncoprotein ProT and tumor suppressor PHAP in apoptosis.     

Can nitrogen input mapping from aerial imagery improve nitrous oxide emissions estimates from grazed grassland?

Precision Agriculture - Most nitrogen (N) lost to the environment from grazed grassland is produced as a result of N excreted by livestock, released in the form of nitrous oxide (N2O) emissions,...     

Effect of combined heat and high-pressure treatments on the texture of chicken breast muscle (pectoralis fundus)

Commercially supplied chicken breast muscle was subjected to simultaneous heat and pressure treatments. Treatment conditions ranged from ambient temperature to 70 degrees C and from 0.1 to 800 MPa, respectively, in various combinations. Texture profile analysis (TPA) of the treated samples was performed to determine changes in muscle hardness. At treatment temperatures up to and including 50 degrees C, heat and pressure acted synergistically to increase muscle hardness. However, at 60 and 70 degrees C, hardness decreased following treatments in excess of 200 MPa. TPA was performed on extracted myofibrillar protein gels that after treatment under similar conditions revealed similar effects of heat and pressure. Differential scanning calorimetry analysis of whole muscle samples revealed that at ambient pressure the unfolding of myosin was completed at 60 degrees C, unlike actin, which completely denatured only above 70 degrees C. With simultaneous pressure treatment at >200 MPa, myosin and actin unfolded at 20 degrees C. Unfolding of myosin and actin could be induced in extracted myofibrillar protein with simultaneous treatment at 200 MPa and 40 degrees C. Electrophoretic analysis indicated high pressure/temperature regimens induced disulfide bonding between myosin chains.     

Phenolics and antioxidative activities in narrow-leafed lupins (Lupinus angustifolius L.)

Eight lupin (Lupinus angustifolius L.) genotypes grown at four locations in south central Alberta in 2004 were evaluated for variability in phenolic constituents and antioxidant activity measured by a photochemiluminescence assay. Genotype was the main source of variation for content of phenolic compounds and antioxidant activities. Phenolic compounds in genotypes varied minimally from 11.9 to 14.7 mg catechin equivalent and 4.15 to 4.95 mg rutin equivalent g(-1) lupin for total phenolic and flavonoid contents, respectively. Lupin genotypes exhibited weak antioxidant activity based on water-soluble substances (ACW) of 0.54 to 1.07 micromole Trolox equivalent antioxidant capacities (TEAC)/g with lag time ranging from 70 to 153 s and an antioxidant index of 6.7 to 14.5 and 1.9 to 3.3 micromole TEAC/g based on measurements of lipid-soluble substances (ACL). Antioxidant activity of lupin genotypes was not related to phenolic contents of seeds.