Search

In the phylogenetic tree of RRM-type Rbps (RNA-binding proteins) in cyanobacteria, Rbp1 of Synechocystis 6803, with a single RRM (RNA recognition motif) region and a C-terminal glycine-rich region, and Rbp2, without the C-terminal region, both belong to the cluster I, whereas Rbp3 with a different type of C-terminal region is in the cluster II. Rbp1 is required for the cold adaptability of the cyanobacterium, and Rbp3 is for salt tolerance. Here, we report that the C-terminal region of Rbp1 is not required for the cold adaptability function but the C-terminal region of Rbp3 can direct the RRM of Rbp1 to the salt tolerance function. Bioinformatic and experimental analyses indicate that Rbps in cyanobacteria should be classified as two types. It is the first report for the distinct roles of C-terminal regions of Rbps in stress tolerance of cyanobacteria. [ABSTRACT FROM AUTHOR]

Objectives: Reducing endoplasmic reticulum stress (ERS)‐induced cardiomyocyte apoptosis is a key strategy for preventing hypertensive heart disease. In our previous study, Icariside II can improve left ventricular remodelling in spontaneously hypertensive rats (SHRs). This study aims to determine whether Icariside II can exert its effect by inhibiting ERS‐induced cardiomyocyte apoptosis via the PERK/ATF‐4/CHOP signalling pathway. Methods: Spontaneously hypertensive rats were randomly divided into model group and Icariside II groups. The rats in the Icariside II groups were intragastrically administrated with Icariside II 4, 8 and 16 mg/kg from 14 to 26 week‐age, respectively. The left ventricular function was measured at the 18, 22 and 26 week‐age by small animal ultrasound. At the end of the 26th week, cardiomyocyte apoptosis was analysed and the levels of GRP78, PERK, ATF‐4 and CHOP gene and protein were detected. Key findings: The function of left ventricular became declined with age in SHRs, but improved in Icariside II groups. Myocardial apoptosis was aggravated in SHRs, but alleviated in Icariside II groups. Icariside II could reduce the levels of GRP78, PERK, ATF‐4, CHOP gene and protein that increased in SHRs. Conclusions: Icariside II prevents hypertensive heart disease by alleviating ERS‐induced cardiomyocyte apoptosis, and its mechanism is related to the impediment of the PERK/ATF‐4/CHOP signalling pathway. [ABSTRACT FROM AUTHOR]