BACKGROUND Congestive heart failure (CHF) is a common cause of atrial fibrillation. Focal sources of unknown mechanism have been described in CHF-related atrial fibrillation. The authors hypothesized that abnormal calcium (Ca(2+)) handling contributes to the CHF-related atrial arrhythmogenic substrate. METHODS AND RESULTS CHF was induced in dogs by ventricular tachypacing (240 bpm x2 weeks). ...

Spliceosomal Prp38 proteins contain a conserved amino-terminal domain, but only higher eukaryotic orthologs also harbor a carboxy-terminal RS domain, a hallmark of splicing regulatory SR proteins. We show by crystal structure analysis that the amino-terminal domain of human Prp38 is organized around three pairs of antiparallel α-helices and lacks similarities to RNA-binding domains found in can...

The purpose of this investigation was to determine whether there is a link between sarcoplasmic reticulum (SR) glycogen status and SR Ca2+ handling. In this investigation, skeletal muscle SR was purified from female Sprague-Dawley rats (200-250 g). Glycogen was extracted from the SR purified from one hindlimb, whereas the SR purified from the contralateral limb served as control. Before removal...

The signal recognition particle and its receptor (SR) target nascent secretory proteins to the ER. SR is a heterodimeric ER membrane protein whose subunits, SR a and SR b , are both members of the GTPase superfamily. Here we characterize a 27-kD protein in Saccharomyces cerevisiae (encoded by SRP102 ) as a homologue of mammalian SR b . This notion is supported ( a ) by Srp102p’s sequence simila...

The endoplasmic reticulum (ER) stress protein mesencephalic astrocyte-derived neurotrophic factor (MANF) has been reported to protect cells from stress-induced cell death before and after its secretion; however, the conditions under which it is secreted are not known. Accordingly, we examined the mechanism of MANF release from cultured ventricular myocytes and HeLa cells, both of which secrete ...

Cyclin-dependent kinase-like kinases (CLKs) are dual specificity protein kinases that phosphorylate Serine/Arginine-rich (SR) proteins involved in pre-mRNA processing. Four CLKs, termed PfCLK-1-4, can be identified in the human malaria parasite Plasmodium falciparum, which show homology with the yeast SR protein kinase Sky1p. The four PfCLKs are present in the nucleus and cytoplasm of the asexu...

The signal recognition particle receptor (SR) is required for the cotranslational targeting of both secretory and membrane proteins to the endoplasmic reticulum (ER) membrane. During targeting, the SR interacts with the signal recognition particle (SRP) which is bound to the signal sequence of the nascent protein chain. This interaction catalyzes the GTP-dependent transfer of the nascent chain ...

SR proteins serve multiple roles in the posttranscriptional control of gene expression, including as regulators of alternative splicing. In this issue of Cell, Xu et al. (2005) demonstrate that a heart-specific knockout of one SR protein, ASF/SF2, produces cardiomyopathy and misregulation of specific alternative splicing events during early postnatal development.

Plant Growth-Promoting Rhizobacteria (PGPR) induce systemic resistance (SR) in plants, decreasing the development of phytopathogens. The FZB42 strain Bacillus velezensis is known to an SR against pathogens various plant species. Previous studies suggested that it could also influence interactions between plants and associated pests. However, insects have developed several strategies counteract ...