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The multiple short introns in Schizosaccharomyces pombe genes with degenerate cis sequences and atypically positioned polypyrimidine tracts make an interesting model to investigate canonical and alternative roles for conserved splicing factors. Here we report functions and interactions of the S. pombe slu7 ؉ (spslu7 ؉ ) gene product, known from Saccharomyces cerevisiae and human in vitro reactions to assemble into spliceosomes after the first catalytic reaction and to dictate 3= splice site choice during the second reaction. By using a missense mutant of this essential S. pombe factor, we detected a range of global splicing derangements that were validated in assays for the splicing status of diverse candidate introns. We ascribe widespread, intron-specific SpSlu7 functions and have deduced several features, including the branch nucleotide-to-3= splice site distance, intron length, and the impact of its A/U content at the 5= end on the intron's dependence on SpSlu7. The data imply dynamic substrate-splicing factor relationships in multiintron transcripts. Interestingly, the unexpected early splicing arrest in spslu7-2 revealed a role before catalysis. We detected a salt-stable association with U5 snRNP and observed genetic interactions with spprp1 ؉ , a homolog of human U5-102k factor. These observations together point to an altered recruitment and dependence on SpSlu7, suggesting its role in facilitating transitions that promote catalysis, and highlight the diversity in spliceosome assembly.T he spliceosome, a ribonucleoprotein machinery, comprising five U snRNPs (U1, U2, U4, U5, and U6) and many accessory proteins, performs the precise recognition and removal of introns from primary RNA polymerase II transcripts. The spliceosome undergoes considerable conformational and compositional changes involving protein-protein, RNA-protein, and RNA-RNA interactions to create the catalytic center and carry out the two catalytic reactions. In the first reaction, cleavage at the 5= splice site (5=ss), forms the following intermediates: a lariat intron-3= exon and a 5= exon. In the second reaction, cleavage at the 3=ss, exon ligation and lariat intron excision occur (1). Intronic cis elements (the 5=ss, branch point sequence [BrP], 3=ss, and polypyrimidine tracts [Pyn tracts]) with flanking exonic sequences guide the recognition and alignment of splice sites. These cis elements differ between species and can influence the splicing mechanism (2, 3). Conceivably, concurrent evolution of splicing machineries with genome evolution is evident in divergent groups, such as fungi and metazoans. The relatively short introns, frequent atypically positioned Pyn tracts (between the 5=ss and BrP), and splicing by intron definition are major features that set the fungal splicing machinery apart from that of metazoans (4, 5).Genetic analyses of Saccharomyces cerevisiae and biochemical studies with both yeast and mammalian cell extracts have given functional insights into several spliceosomal factors and snRNPs. In vivo and in vitro studie...

Alpha1-antitrypsin (AAT) is one of the major circulating anti-protease whose levels in circulation are raised during excessive amount of proteases, especially neutrophil elastase (NE) released during the course of inflammation. Proteolytic attack of NE on peripheral organs, more exclusively on lung parenchyma has severe consequence that may precipitate pulmonary emphysema. Normally, human body has its own molecular and physiological mechanisms to synthesize and regulate the production of anti-protease like AAT to mitigate the extent of inflammatory damage. AAT coded by serine-protease inhibitor (SERPINA1) is predominantly expressed in hepatocytes and to some extent by macrophages, monocytes, lung tissue etc. The observation that persons with AAT deficiency developed chronic obstructive pulmonary disease (COPD) and early-onset of emphysema proposed a role for pathways connecting AAT in pathogenesis. Extensive studies have been done till now to bridge a connection between numerous genetic polymorphisms of SERPINA1 gene and the early onset of COPD. Here in this review, we have comprehensively discussed some of the variants of SERPINA1 gene discovered till date and their association with the exacerbation of obstructive pulmonary disease.

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The biotechnological uses of algae and cyanobacteria have been widely discussed in the context of climate change and consequent efforts to circularize economies, minimize carbon release and reuse waste streams. Their great potential in bioproduction and bioremediation has barely been exploited, particularly for the well-characterized red algae Galdieria sulphuraria and Cyanidioschyzon merolae. These and other Cyanidiales are excellent candidates for biotechnological enhancement and metabolic engineering for a broad spectrum of applications including the production of biofuels and thermostable colourants. In particular, extremophily, such as growth at thermophilic temperaturesup to 60°Cand at low pH and high salinity, make these algae unusually resistant to contamination and pathogens, and therefore potentially more commercially viable. We review existing applications of the Cyanidiales, as well as their available molecular tools. Their varied nutritional demands, from the broad heterotrophy of G. sulphuraria to strongly autotrophic C. merolae, along with their ability to grow to high densities, confer great potential as expression hosts. We also discuss the deficiencies that must be overcome to unlock further applications and ultimately to embed thermophilic red algae into a framework of circular and sustainable economic activity relying on bio-based sources.

Alpha1-antitrypsin (α1AT) is an abundant serine-protease inhibitor in circulation. It has an important role in neutralizing the neutrophil elastase activity. Different pathogenic point mutations like Z(E342K)-α1AT have been implicated in the development of liver cirrhosis and Chronic Obstructive Pulmonary Disease (COPD), the latter being a cluster of progressive lung diseases including chronic bronchitis and emphysema. M3-α1AT (376Glu > Asp) is another variant of α1AT which so far is largely being considered as normal though increased frequency of the variant has been reported in many human diseases including COPD. We also observed increased frequency of M3-α1AT in COPD cases in Kashmiri population. The frequency of heterozygous (AC) genotype in cases and controls was 58.57% and 27.61% (odds-ratio 6.53 (2.27–15.21); p < 0.0001) respectively, while homozygous CC genotype was found to be 21.42% and 6.66% (odds-ratio 10.56 (3.63–18.64); p < 0.0001) respectively. Comparative in vitro investigations that include trypsin‒antitrypsin assay, Circular Dichroism spectroscopy and dynamic light scattering performed on wild-type (M-α1AT), M3-α1AT, and Z-α1AT proteins along with the molecular dynamics simulations revealed that M3-α1AT has properties similar to Z-α1AT capable of forming aggregates of varied size. Our maiden observations suggest that M3-α1AT may contribute to the pathogenesis of COPD and other disorders by mechanisms that warrant further investigations.

Graphical abstractSchematic representation of compounds isolated from Ajuga bracteosa and their antimutagenic activity.