JAYANTA K PAL
Articles written in Journal of Biosciences
Volume 20 Issue 2 June 1995 pp 197-209
Prosomes and multicatalytic proteinases were purified from rabbit erythrocyte lysates and were analysed to determine their relationship. During purification by sucrose density gradient centrifugation using low salt buffer, they sedimented at 20–26S. Upon further purification, using high salt buffer, prosomes were recovered as 20S complexes as determined by their characteristic polypeptide pattern. Interestingly, both the 26S and 20S components had protease activity. Therefore, in order to determine their relationship with the multicatalytic proteinases, which are reported to contain a similar set of polypeptides, highly pure prosomes and the multicatalytic proteinases were analysed. Both 20S prosomes and multicatalytic proteinases showed protease activity and also had identical protein subunits of molecular weight ranging from 21 kDa to 35 kDa. Among these, at least two were immunologically identical as determined by Western blot using two monoclonal antibodies prepared against duck prosomes. Furthermore, protease activities of both components were inhibited almost to the same extent by an endogenous inhibitor specific for high molecular weight proteases and calpain. These results thus establish that the 20S prosomes and multicatalytic proteinases are identical, and suggest further that proteolytic activity could be the principal function of prosomes.
Volume 23 Issue 4 October 1998 pp 353-360
Heat shock protein 90 (Hsp90), an abundant and ubiquitous cytoplasmic protein has recently been indicated to participate in the regulation of protein synthesis by interacting with the heme-regulated eukaryotic initiation factor 2α (eIF-2α) kinase, also known as the heme-regulated inhibitor (HRI). However, there exists an ambiguity on the exact nature of its action. In this investigation, the interaction of Hsp90 and HRI has been examined both
Volume 42 Issue 1 March 2017 pp 189-207 Review
Protozoan parasites are one of the oldest living entities in this world that throughout their existence have shown excellentresilience to the odds of survival and have adapted beautifully to ever changing rigors of the environment. In view of thedynamic environment encountered by them throughout their life cycle, and in establishing pathogenesis, it is unsurprisingthat modulation of gene expression plays a fundamental role in their survival. In higher eukaryotes, untranslated regions(UTRs) of transcripts are one of the crucial regulators of gene expression (influencing mRNA stability and translationefficiency). Parasitic protozoan genome studies have led to the characterization (in silico, in vitro and in vivo) of a largenumber of their genes. Comparison of higher eukaryotic UTRs with parasitic protozoan UTRs reveals the existence ofseveral similar and dissimilar facets of the UTRs. This review focuses on the elements of UTRs of medically importantprotozoan parasites and their regulatory role in gene expression. Such information may be useful to researchers in designinggene targeting strategies linked with perturbation of host-parasite relationships leading to control of specific parasites.