MYC-type transcription factors, MYC67 and MYC70, interact with ICE1 and negatively regulate cold tolerance in Arabidopsis

The expression of hundreds of genes is induced by low temperatures via a cold signaling pathway. ICE1, a MYC-type transcription factor, plays an important role in the induction of CBF3/DREB1A to control cold-responsive genes and cold tolerance. To elucidate other molecular factors, a yeast 2-hybrid screening was performed. Two MYC-type transcription factors, MYC67 and MYC70, were identified as ICE1-interacting proteins. The myc mutants were more tolerant to freezing temperatures than wild type. CBF3/DREB1A and other cold-responsive genes were up-regulated in the myc mutants. Overexpression of the MYC genes increased the cold sensitivity and down-regulated the expression of cold-responsive genes. The MYC proteins interacted with the cis-elements in the CBF3/DREB1A promoter, probably to interfere interaction between ICE1 and the cis-elements. Taken together, these results demonstrate that MYC67 and MYC70, ICE1 interactors, negatively regulate cold-responsive genes and cold tolerance

NPR3 and NPR4 are receptors for the immune signal salicylic acid in plants

Salicylic acid (SA) is a plant immune signal produced upon pathogen challenge to induce systemic acquired resistance (SAR). It is the only major plant hormone for which the receptor has not been firmly identified. SAR in Arabidopsis requires the transcription cofactor NPR1 (nonexpresser of PR genes 1), whose degradation serves as a molecular switch for SAR. Here we show that NPR1 paralogues, NPR3 and NPR4, are SA receptors that bind SA with different affinities and function as adaptors of the Cullin 3 ubiquitin E3 ligase to mediate NPR1 degradation in an SA-regulated manner. Accordingly, the npr3 npr4 mutant accumulates higher levels of NPR1 and is insensitive to SAR induction. Moreover, this mutant is defective in pathogen effector-triggered programmed cell death and immunity. Our study reveals the mechanism of SA perception in determining cell death and survival in response to pathogen challenge

赤芽球癆を合併したT-cell large granular lymphocyte leukemia の一例

T-cell large granular lymphocyte leukemia は長期(6か月以上)にわたる末梢血中の著明な大顆粒リンパ球(large granular lymphocyte;以下,LGL)のモノクローナルな増加によって特徴づけられる疾患で,しばしば赤芽球癆を伴うことが知られている.今回,我々はHCV陽性肝硬変患者に赤芽球癆を合併したT-LGLの1例を経験した.末梢血および骨髄塗抹標本では細胞質内に微細なアズール顆粒を有し,核異型を示すリンパ球の増加がみられ,末梢血および骨髄のフローサイトメトリーおよび骨髄吸引クロット標本の免疫組織化学で,CD3,CD8,CD57陽性リンパ球の増加が確認された.骨髄細胞のPCRではTCRβの再構成を認めず,TCRγおよびTCRδの再構成がみられた.またプレドニゾロン治療にてCD57陽性リンパ球の減少および赤芽球造血の回復が確認されたことから,赤芽球癆を合併したγδT-LGLと診断した.最近,T-LGLにはSTAT3あるいはSTAT5bのSHドメインの遺伝子変異が高頻度にみられることが報告されているが,本症例においては,これらの遺伝子変異は確認できなかった.T-cell large granular lymphocytic leukemia (T-LGL) is characterized by marked increase of monoclonal large granular lymphocytes (LGL) in the peripheral blood over the long term (6 months or more). It has been reported about 20% cases of T-LGL cases are associated with pure red cell aplasia (PRCA). Here, we describe a case of T-LGL associated with PRCA. This case was characterized by increase in the number of CD3+,CD8+,CD57+, and granzyme B-positive lymphocytes with fine azurophilic cytoplasmic granules and nuclear atypia in peripheral blood and bone marrow. The patient was diagnosed havingγδT-LGL because T-cell receptor (TCR)γ and TCRδ gene but not TCRβ gene rearrangement was detected by the PCR of the bone marrow cells. Prednisolone administration decreased in number of the LGL cells, accompanying recover of erythropoiesis. Although somatic mutations in the Src homology 2 domain of STAT3 or STAT5b gene are reported in 70% percent of the T-LGL with PRCA, such STAT mutations could not be detected in this case

10-year follow-up of congenital cytomegalovirus infection complicated with severe neurological findings in infancy: a case report

Abstract Background Congenital cytomegalovirus (cCMV) infection leads to sensorineural hearing loss (SNHL) and neurodevelopmental delays. However, the long-term outcomes of cCMV infection with severe neurological manifestations in infancy remain unclear. Case presentation The patient was a one-month-old girl visited owing to abnormalities in neonatal hearing screening. Central nervous system involvement including intracranial calcification and extensive white matter abnormalities was identified. Right SNHL (50 dB) was detected by auditory brain response (ABR) testing. The cause of her hearing loss was determined to be cCMV infection by polymerase chain reaction (PCR) using a dried blood spot. At 1.5 months of age, the patient was treated with intravenous ganciclovir (GCV) for 5 weeks followed by oral valganciclovir (VGCV) for an additional 6 weeks. Cytomegalovirus (CMV) loads in her urine continued to be detected until she was 10 years old. Fortunately, during this time, her right hearing loss did not deteriorate, and her left hearing remained normal. Furthermore, the extensive abnormal areas of white matter observed at 1 month of age mostly disappeared by the time the patient was 9 years old. Her neurodevelopmental score was normal, and motor milestones were not delayed as of 10 years of age. Conclusions Here, we report the 10-year follow-up of a patient with cCMV who showed normal neurodevelopment, no progression of hearing loss, and ameliorating magnetic resonance imaging (MRI) findings, despite having various complications and severe neurological findings during infancy