Visual and functional demonstration of growing Bax-induced pores in mitochondrial outer membranes.

Bax induces mitochondrial outer membrane permeabilization (MOMP), a critical step in apoptosis in which proteins are released into the cytoplasm. To resolve aspects of the mechanism, we used cryo-electron microscopy (cryo-EM) to visualize Bax-induced pores in purified mitochondrial outer membranes (MOMs). We observed solitary pores that exhibited negative curvature at their edges.

Apoptosis regulation at the mitochondrial outer membrane.

Mitochondria play a critical role in apoptosis, or programmed cell death, by releasing apoptogenic factors from the intermembrane space. This process, known as mitochondrial outer membrane permeabilization (MOMP), is tightly regulated by the Bcl-2 family proteins. Pro-apoptotic Bcl-2 family members, Bax and Bak, change their conformation when activated by BH3 domain-only proteins in the family and permeabilize the MOM, whereas pro-survival members inhibit permeabilization.

Manipulation of culture conditions alters lipid content and fatty acid profiles of a wide variety of known and new oleaginous yeast species.

Oleaginous yeasts have been studied for oleochemical production for over 80 years. Only a few species have been studied intensely. To expand the diversity of oleaginous yeasts available for lipid research, we surveyed a broad diversity of yeasts with indicators of oleaginicity including known oleaginous clades, and buoyancy.

Multiple precursor ion scanning of gangliosides and sulfatides with a reversed-phase microfluidic chip and quadrupole time-of-flight mass spectrometry.

Precise profiling of polar lipids including gangliosides and sulfatides is a necessary step in understanding the diverse physiological role of these lipids. We have established an efficient method for the profiling of polar lipids using reversed-phase nano high-performance liquid chromatography microfluidic chip quadrupole time-of-flight mass spectrometry (nano-HPLC-chip Q-TOF/MS). A microfluidic chip design provides improved chromatographic performance, efficient separation, and stable nanospray while the advanced high-resolution mass spectrometer allowed for the identification of complex isobaric polar lipids such as NeuAc- and NeuGc-containing gangliosides.

Intakes and breast-milk concentrations of essential fatty acids are low among Bangladeshi women with 24-48-month-old children.

Maternal fat intake and adipose reserves are major sources of PUFA during lactation. The present study examined the cross-sectional relationship between prolonged breast-feeding and maternal BMI, assessed adequacy of fat intake among lactating and non-lactating mothers of children 24-48 months of age and determined breast-milk fatty acid composition. Multi-stage sampling was used to select a representative sample of mothers from two rural districts in Bangladesh (n 474).

The sphingosine 1-phosphate receptor 5 and sphingosine kinases 1 and 2 are localised in centrosomes: possible role in regulating cell division.

We show here that the endogenous sphingosine 1-phosphate 5 receptor (S1P(5), a G protein coupled receptor (GPCR) whose natural ligand is sphingosine 1-phosphate (S1P)) and sphingosine kinases 1 and 2 (SK1 and SK2), which catalyse formation of S1P, are co-localised in the centrosome of mammalian cells, where they may participate in regulating mitosis. The centrosome is a site for active GTP-GDP cycling involving the G-protein, G(i) and tubulin, which are required for spindle pole organization and force generation during cell division. Therefore, the presence of S1P(5) (which normally functions as a plasma membrane guanine nucleotide exchange factor, GEF) and sphingosine kinases in the centrosome might suggest that S1P(5) may function as a ligand activated GEF in regulating G-protein-dependent spindle formation and mitosis.

Chemo-enzymatic detection of protein isoaspartate using protein isoaspartate methyltransferase and hydrazine trapping.

Isoaspartate formation is a ubiquitous post-translation modification arising from spontaneous asparagine deamidation or aspartate isomerization. The formation of isoaspartate inserts a methylene group into the protein backbone, generating a "kink", and may drastically alter protein structure and function, thereby playing critical roles in a myriad of biological processes, human diseases, and protein pharmaceutical development. Herein, we report a chemo-enzymatic detection method for the isoaspartate protein, which in particular allows the affinity enrichment of isoaspartate-containing proteins.

Lipidomics and lipid profiling in metabolomics.

Purpose Of Review: The field of metabolomics is extending the principles of genomics into cellular and organism metabolism and driving a revolution in lipid biochemistry, physiology and nutrition. Lipids studied using metabolomic approaches - lipidomics - are an ideal subject for metabolomic measurements.

Recent Findings: Lipids are small molecules that share common physical and chemical properties as a class, whose presence and abundance are key to much of metabolic regulation, from subcellular compartments to whole body energy control and signaling.