Browsing by Author "Mishra, Poonam"

Now showing 1 - 5 of 5

Comparative analysis of sequence-structure function relationship of the SUN-domain protein CaSUN1
(OMICS International, 2017) Mishra, Poonam; Wardhan, Vijay; Pandey, Aarti; Chakraborty, Subhra; Garg, Gunjan; Chakraborty, Niranjan
Sad1/UNC-84 (SUN)-domain proteins are residents of inner nuclear membrane (INM), and share structural features across species. We previously reported a highly conserved C-terminal SUN-domain family protein, designated CaSUN1, in the stress-responsive proteomic landscape of a grain legume, chickpea. In this study, we identified two other chickpea SUN proteins, CaSUN2 and CaSUN3, and performed a comparative analysis of the sequence-structure-function relationship to better understand the diversification of SUN-domain superfamily proteins. Sequence similarity across the species was investigated using multiple sequence alignment, which showed conserved patterns between CaSUN1 and the homologs. Phylogenetic analysis showed that plant SUN-domain proteins are clustered in a unique and distinct group. Using ab-initio approach, a 3D protein structure was generated and further validated using various tools including the Ramachandran plot. The results displayed 90.1% of the Ã Â and Ã Â± residues angles in the most favoured regions, suggesting a high-quality structural model for CaSUN1. Model deviation and fluctuation analysis were performed using molecular dynamics (MD) simulation of CaSUN1. The secondary structure analysis of CaSUN revealed a similarity between the structural components shared among them. CaSUN1 revealed two functional domains viz., SUN and muskelin, and the presence of kelch-repeat domain pointed out its putative role in oligomerization, while its binding affinity with different ligands indicates diverse functions. These results would not only give deeper insights into the structure-function relationships within the SUNsuperfamily proteins, but also their putative physiological roles.
Genetics of flowering time in bread wheat Triticum aestivum: complementary interaction between vernalization-insensitive and photoperiod-insensitive mutations imparts very early flowering habit to spring wheat
(Indian Academy of Sciences, 2012) Kumar, Sushil; Sharma, Vishakha; Chaudhary, Swati; Tyagi, Anshika; Mishra, Poonam
Time to flowering in the winter growth habit bread wheat is dependent on vernalization (exposure to cold conditions) and exposure to long days (photoperiod). Dominant Vrn-1 (Vrn-A1, Vrn-B1 and Vrn-D1) alleles are associated with vernalization independent spring growth habit. The semidominant Ppd-D1a mutation confers photoperiod-insensitivity or rapid flowering in wheat under short day and long day conditions. The objective of this study was to reveal the nature of interaction between Vrn-1 and Ppd-D1a mutations (active alleles of the respective genes vrn-1 and Ppd-D1b). Twelve Indian spring wheat cultivars and the spring wheat landrace Chinese Spring were characterized for their flowering times by seeding them every month for five years under natural field conditions in New Delhi. Near isogenic Vrn-1 Ppd-D1 and Vrn-1 Ppd-D1a lines constructed in two genetic backgrounds were also phenotyped for flowering time by seeding in two different seasons. The wheat lines of Vrn-A1a Vrn-B1 Vrn-D1 Ppd-D1a, Vrn-A1a Vrn-B1 Ppd-D1a and Vrn-A1a Vrn-D1 Ppd-D1a (or Vrn-1 Ppd-D1a) genotypes flowered several weeks earlier than that of Vrn-A1a Vrn-B1 Vrn-D1 Ppd-D1b, Vrn-A1b Ppd-D1b and Vrn-D1 Ppd-D1b (or Vrn-1 Ppd-D1b) genotypes. The flowering time phenotypes of the isogenic vernalization-insensitive lines confirmed that Ppd-D1a hastened flowering by several weeks. It was concluded that complementary interaction between Vrn-1 and Ppd-D1a active alleles imparted super/very-early flowering habit to spring wheats. The early and late flowering wheat varieties showed differences in flowering time between short day and long day conditions. The flowering time in Vrn-1 Ppd-D1a genotypes was hastened by higher temperatures under long day conditions. The ambient air temperature and photoperiod parameters for flowering in spring wheat were estimated at 25°C and 12 h, respectively.
Interaction between COCHLEATA and UNIFOLIATA genes enables normal flower morphogenesis in the garden pea, Pisum sativum
(Indian Academy of Sciences, 2011) Kumar, Sushil; Sharma, Vishakha; Chaudhary, Swati; Kumari, Renu; Kumari, Nisha; Mishra, Poonam
The simple stipules, leaflet and tendril bearing imparipinnately compound leaf blades and zygomorphic flowers, produced on stems of the diploid (2n = 14; ≥ 5000 Mbp nuclear genome) papilionoid Fabaceae plant Pisum sativum, are serving as unique and highly informative models for the dis- section of plant developmental programmes. The growing information has revealed that the processes of stipule, leaf and flower morphogeneses are genetically interconnected in P. sativum (Hofer et al. 1997; Yaxley et al. 2001; Wang et al.2008; Kumar et al. 2009).
Membrane-associated proteomics of chickpea identifies Sad1/UNC-84 protein (CaSUN1), a novel component of dehydration signaling
(Nature Publishing Group, 2014) Jaiswal, Dinesh Kumar; Mishra, Poonam; Subba, Pratigya; Rathi, Divya; Chakraborty, Subhra; Chakraborty, Niranjan
Dehydration affects almost all the physiological processes including those that result in the accumulation of misfolded proteins in the endoplasmic reticulum (ER), which in turn elicits a highly conserved signaling, the unfolded protein response (UPR). We investigated the dehydration-responsive membrane-associated proteome of a legume, chickpea, by 2-DE coupled with mass spectrometry. A total of 184 protein spots were significantly altered over a dehydration treatment of 120 h. Among the differentially expressed proteins, a non-canonical SUN domain protein, designated CaSUN1 (Cicer arietinum Sad1/UNC-84), was identified. CaSUN1 localized to the nuclear membrane and ER, besides small vacuolar vesicles. The transcripts were downregulated by both abiotic and biotic stresses, but not by abscisic acid treatment. Overexpression of CaSUN1 conferred stress tolerance in transgenic Arabidopsis. Furthermore, functional complementation of the yeast mutant, slp1, could rescue its growth defects. We propose that the function of CaSUN1 in stress response might be regulated via UPR signaling.
Proteomic analysis reveals the diversity and complexity of membrane proteins in chickpea (Cicer arietinum L.)
(BioMed Central, 2012) Jaiswal, Dinesh Kumar; Ray, Doel; Subba, Pratigya; Mishra, Poonam; Gayali, Saurabh; Datta, Asis; Chakraborty, Subhra; Chakraborty, Niranjan
Compartmentalization is a unique feature of eukaryotes that helps in maintaining cellular homeostasis not only in intra- and inter-organellar context, but also between the cells and the external environment. Plant cells are highly compartmentalized with a complex metabolic network governing various cellular events. The membranes are the most important constituents in such compartmentalization, and membrane-associated proteins play diverse roles in many cellular processes besides being part of integral component of many signaling cascades.