Rcf1 and Rcf2, members of the hypoxia-induced gene 1 protein family, are critical components of the mitochondrial cytochrome bc1-cytochrome c oxidase supercomplex

We report that Rcf1 (formerly Aim31), a member of the conserved hypoxia-induced gene 1 (Hig1) protein family, represents a novel component of the yeast cytochrome bc(1)-cytochrome c oxidase (COX) supercomplex. Rcf1 (respiratory supercomplex factor 1) partitions with the COX complex, and evidence that it may act as a bridge to the cytochrome bc(1) complex is presented. Rcf1 interacts with the Cox3 subunit and can do so prior to their assembly into the COX complex. A close proximity of Rcf1 and members of the ADP/ATP carrier (AAC) family was also established. Rcf1 displays overlapping function with another Hig1-related protein, Rcf2 (formerly Aim38), and their joint presence is required for optimal COX enzyme activity and the correct assembly of the cytochrome bc(1)-COX supercomplex. Rcf1 and Rcf2 can independently associate with the cytochrome bc(1)-COX supercomplex, indicating that at least two forms of this supercomplex exist within mitochondria. We provide evidence that the association with the cytochrome bc(1)-COX supercomplex and regulation of the COX complex are a conserved feature of Hig1 family members. Based on our findings, we propose a model where the Hig1 proteins regulate the COX enzyme activity through Cox3 and associated Cox12 protein, in a manner that may be influenced by the neighboring AAC proteins.     

Neural Processing of Emotional Facial and Semantic Expressions in Euthymic Bipolar Disorder (BD) and Its Association with Theory of Mind (ToM)

Background

Adults with bipolar disorder (BD) have cognitive impairments that affect face processing and social cognition. However, it remains unknown whether these deficits in euthymic BD have impaired brain markers of emotional processing.

Methodology/Principal Findings

We recruited twenty six participants, 13 controls subjects with an equal number of euthymic BD participants. We used an event-related potential (ERP) assessment of a dual valence task (DVT), in which faces (angry and happy), words (pleasant and unpleasant), and face-word simultaneous combinations are presented to test the effects of the stimulus type (face vs word) and valence (positive vs. negative). All participants received clinical, neuropsychological and social cognition evaluations. ERP analysis revealed that both groups showed N170 modulation of stimulus type effects (face > word). BD patients exhibited reduced and enhanced N170 to facial and semantic valence, respectively. The neural source estimation of N170 was a posterior section of the fusiform gyrus (FG), including the face fusiform area (FFA). Neural generators of N170 for faces (FG and FFA) were reduced in BD. In these patients, N170 modulation was associated with social cognition (theory of mind).

Conclusions/Significance

This is the first report of euthymic BD exhibiting abnormal N170 emotional discrimination associated with theory of mind impairments.     

Heart Failure Induces Significant Changes in Nuclear Pore Complex of Human Cardiomyocytes

Aims

The objectives of this study were to analyse the effect of heart failure (HF) on several proteins of nuclear pore complex (NPC) and their relationship with the human ventricular function.

Methods and Results

A total of 88 human heart samples from ischemic (ICM, n = 52) and dilated (DCM, n = 36) patients undergoing heart transplant and control donors (CNT, n = 9) were analyzed by Western blot. Subcellular distribution of nucleoporins was analysed by fluorescence and immunocytochemistry. When we compared protein levels according to etiology, ICM showed significant higher levels of NDC1 (65%, p<0.0001), Nup160 (88%, p<0.0001) and Nup153 (137%, p = 0.004) than those of the CNT levels. Furthermore, DCM group showed significant differences for NDC1 (41%, p<0.0001), Nup160 (65%, p<0.0001), Nup153 (155%, p = 0.006) and Nup93 (88%, p<0.0001) compared with CNT. However, Nup155 and translocated promoter region (TPR) did not show significant differences in their levels in any etiology. Regarding the distribution of these proteins in cell nucleus, only NDC1 showed differences in HF. In addition, in the pathological group we obtained good relationship between the ventricular function parameters (LVEDD and LVESD) and Nup160 (r = −0382, p = 0.004; r = −0.290, p = 0.033; respectively).

Conclusions

This study shows alterations in specific proteins (NDC1, Nup160, Nup153 and Nup93) that compose NPC in ischaemic and dilated human heart. These changes, related to ventricular function, could be accompanied by alterations in the nucleocytoplasmic transport. Therefore, our findings may be the basis for a new approach to HF management.     

Granulocyte-macrophage stimulating factor (GM-CSF) increases circulating dendritic cells but does not abrogate suppression of adaptive cellular immunity in patients with metastatic colorectal cancer receiving chemotherapy

Background  

Advanced cancer and chemotherapy are both associated with immune system suppression. We initiated a clinical trial in patients receiving chemotherapy for metastatic colorectal cancer to determine if administration of GM-CSF in this setting was immunostimulatory.     

Host selection by the wheat stem sawfly in winter wheat and the role of semiochemicals mediating oviposition preference

The wheat stem sawfly (WSS), Cephus cinctus Norton (Hymenoptera: Cephidae), causes significant damage in cereal crops in the northern Great Plains of North America. This study assessed oviposition preference in winter wheat, Triticum aestivum L. (Poaceae), and investigated how it is affected by the emission of semiochemicals, with the overall goal of enhancing trap crop efficacy. We studied five winter wheat cultivars that could be recommended as trap crops for WSS and compared them with regards to agronomic characteristics influencing oviposition behavior and their emission of behaviorally active volatiles. Subsequently, we evaluated oviposition preference on three selected cultivars, ‘Norstar’, ‘Neeley’, and ‘Rampart’, using choice tests at two plant growth stages. Most eggs were found in Norstar at both stages tested when females were exposed to the three cultivars simultaneously making it the preferred choice for a trap crop. Norstar also emitted more behaviorally active volatiles, primarily (E)‐ and (Z)‐β‐ocimene. The results for the effect of main stem height or diameter on oviposition was inconsistent between infested vs. uninfested stems within cultivars, although there was a correlation between infestation and height for younger plants. These results show that these agronomic characteristics, typically viewed as explanatory, did not clearly explain oviposition preference and suggest a role of β‐ocimene in determining suitability for oviposition among these cultivars. This study supports previous findings suggesting oviposition preference in winter wheat involves several cues, including stem height and volatile attractants that may be important in determining suitability.     

Automated detection of covalent adducts to human serum albumin by immunoaffinity chromatography, on-line solution phase digestion and liquid chromatography-mass spectrometry

A generic method for the detection of covalent adducts to the cysteine-34 residue of human serum albumin (HSA) has been developed, based on an on-line combination of immunoaffinity chromatography for selective sample pre-treatment, solution phase digestion, liquid chromatography and tandem mass spectrometry. Selective anti-HSA antibodies immobilized on agarose were used for sample pre-concentration and purification of albumin from the chemically produced alkylated HSA. After elution, HSA and HSA adducts are mixed with pronase and directed to a reaction capillary kept at a digestion temperature of 70 degrees C. The digestion products were trapped on-line on a C18 SPE cartridge. The peptides were separated on a reversed-phase column using a gradient of organic modifier and subsequently detected using tandem mass spectrometry. Modified albumin samples consisted of synthetically alkylated HSA by the reactive metabolite of acetaminophen, N-acetyl-p-benzoquinoneimine (NAPQI), and using the alkylating agent 1-chloro-2,4-dinitrobenzene (CDNB) as reference. The resulting mixture of alkylated versus non-modified albumin has been applied to the on-line system, and alkylation of HSA is revealed by the detection of the modified marker tetra-peptide glutamine-cysteine-proline-phenylalanine (QCPF) adducts NAPQI-QCPF and CDNB-QCPF. Detection of alkylated species was enabled by the use of data comparison algorithms to distinguish between unmodified and modified HSA samples. The in-solution digestion proved to be a useful tool for enabling fast (less than 2 min) and reproducible on-line digestion of HSA. A detection limit of 1.5 micromol/L of modified HSA could be obtained by applying 10 microL of NAPQI-HSA sample.     

Light Regulates Plant Alternative Splicing through the Control of Transcriptional Elongation

1. Download high-res image (143KB)
2. Download full-size image

     

MAP4K4 Inhibition Promotes Survival of Human Stem Cell-Derived Cardiomyocytes and Reduces Infarct Size In Vivo

1. Download high-res image (236KB)
2. Download full-size image