Prevalence of astrovirus and parvovirus in Japanese domestic cats.

Feces obtained from 204 domestic cats with gastrointestinal symptoms were genetically examined for feline astrovirus (FeAstV) and feline parvovirus (FPV), both of which are known feline gastroenteric viruses. FeAstV detection rates were significantly higher in winter (44.4%) than in other seasons, and in cats under a year old (27.

Adaptation-induced collective dynamics of a single-cell protozoan.

We investigate the behavior of a single-cell protozoan in a narrow tubular ring. This environment forces them to swim under a one-dimensional periodic boundary condition. Above a critical density, single-cell protozoa aggregate spontaneously without external stimulation.

BBF2H7, a novel transmembrane bZIP transcription factor, is a new type of endoplasmic reticulum stress transducer.

Endoplasmic reticulum (ER) stress transducers IRE1 (inositol requiring 1), PERK (PKR-like endoplasmic reticulum kinase), and ATF6 (activating transcription factor 6) are well known to transduce signals from the ER to the cytoplasm and nucleus when unfolded proteins accumulate in the ER. Recently, we identified OASIS (old astrocyte specifically induced substance) as a novel ER stress transducer expressed in astrocytes. We report here that BBF2H7 (BBF2 human homolog on chromosome 7), an ER-resident transmembrane protein with the bZIP domain in the cytoplasmic portion and structurally homologous to OASIS, is cleaved at the membrane in response to ER stress.

Autophagy is activated for cell survival after endoplasmic reticulum stress.

Eukaryotic cells deal with accumulation of unfolded proteins in the endoplasmic reticulum (ER) by the unfolded protein response, involving the induction of molecular chaperones, translational attenuation, and ER-associated degradation, to prevent cell death. Here, we found that the autophagy system is activated as a novel signaling pathway in response to ER stress. Treatment of SK-N-SH neuroblastoma cells with ER stressors markedly induced the formation of autophagosomes, which were recognized at the ultrastructural level.

Cleavage of the membrane-bound transcription factor OASIS in response to endoplasmic reticulum stress.

When unfolded or misfolded proteins accumulate in the endoplasmic reticulum (ER), unfolded protein response (UPR) signals are transmitted from the ER to the nucleus and cytoplasm to facilitate protein folding. OASIS (old astrocyte specifically induced substance) is an ER stress transducer in astrocytes, a membrane-bound transcription factor that activates genes in the ER stress response. When unfolded proteins accumulate in the ER, OASIS is cleaved at the membrane to release its cytoplasmic domain, which then enters the nucleus and activates target genes.

Candidates for tumor-specific alternative splicing.

Gene expression can be regulated not only by transcription and post-transcriptional modifications, but also by splicing regulation. Recent genome-wide analyses have indicated that up to 70% of human genes may have alternatively spliced forms, suggesting that splicing regulation affects a wide range of gene expression. Tumor tissues show significantly altered protein expressions, and this is also thought to be affected by alternative splicing.

XBP1 activates the transcription of its target genes via an ACGT core sequence under ER stress.

In mammals, the transmembrane protein kinase/endoribonuclease IRE1 is activated by endoplasmic reticulum stress and subsequently processes XBP1 mRNA to generate an active form of XBP1 protein. The spliced form of XBP1 protein acts as a transcription factor and induces the expression of ER-resident molecular chaperones. However, the mechanism for how XBP1 promotes the transcription of its target genes as well as the cis-acting elements for XBP1 during ER stress has been unclear.

OASIS, a CREB/ATF-family member, modulates UPR signalling in astrocytes.

Endoplasmic reticulum (ER) stress transducers IRE1, PERK and ATF6 are well known to transduce signals from the ER to the cytoplasm and nucleus when unfolded proteins are accumulated in the ER. Here, we identified OASIS as a novel ER stress transducer. OASIS is a basic leucine zipper (bZIP) transcription factor of the CREB/ATF family with a transmembrane domain that allows it to associate with the ER.

Identification of regulatory cis-acting elements for alternative splicing of presenilin 2 exon 5 under hypoxic stress conditions.

An alternatively spliced form of the presenilin 2 (PS2) gene lacking exon 5 (PS2V) was found in human brains with sporadic Alzheimer's disease. PS2V was induced by hypoxic stress in human neuroblastoma SK-N-SH cells, indicating that hypoxic stress affects the splicing machineries for PS2 exon 5. Here, we identified the critical cis-acting element (sec 2) on the PS2 pre-mRNA responsible for the aberrant splicing of PS2 exon 5 under hypoxic stress conditions.

Ca(2+)-dependent and caspase-3-independent apoptosis caused by damage in Golgi apparatus due to 2,4,5,7-tetrabromorhodamine 123 bromide-induced photodynamic effects.

To clarify the role of the Golgi apparatus in photodynamic therapy-induced apoptosis, its signaling pathway was studied after photodynamic treatment of human cervix carcinoma cell line HeLa, in which a photosensitizer, 2,4,5,7-tetrabromorhodamine 123 bromide (TBR), was incorporated into the Golgi apparatus. Laser scanning microscopic analysis of TBR-loaded HeLa cells confirmed that TBR was exclusively located in the Golgi apparatus. HeLa cells incubated with TBR for 1 h were then exposed to visible light using an Xe lamp.