A previously unrecognized nonmuscle myosin II heavy chain (NMHC II), which constitutes a distinct branch of the nonmuscle/smooth muscle myosin II family, has recently been revealed in genome data bases. We characterized the biochemical properties and expression patterns of this myosin. Using nucleotide probes and affinity-purified antibodies, we found that the distribution of NMHC II-C mRNA and protein (MYH14) is widespread in human and mouse organs but is quantitatively and qualitatively distinct from NMHC II-A and II-B. In contrast to NMHC II-A and II-B, the mRNA level in human fetal tissues is substantially lower than in adult tissues. Immunofluorescence microscopy showed distinct patterns of expression for all three NMHC iso-

Ablation of nonmuscle myosin (NM) II-B and II-C in mice results in a defect in cardiac myocyte karyokinesis. More than 90% of the double knockout cardiac myocytes demonstrate defects in chromatid segregation and mitotic spindle formation. The requirement for NM II in karyokinesis is demonstrated in both the intact heart and in HL-1 atrial myocytes in culture.

RNA interference (RNAi) treatment of monkey COS-7 cells, a cell line that lacks nonmuscle myosin heavy chain II-A (NMHC II-A) but contains NMHC II-B and II-C, was used to investigate the participation of NMHC isoforms in cytokinesis. We specifically suppressed the expression of NMHC II-B or II-C using 21 nucleotide small interfering RNA (siRNA) duplexes. Down-regulation of NMHC II-B protein expression to 10.2 ؎ 0.7% inhibited COS-7 cell proliferation by 50% in the RNAitreated cells compared with control cells. Moreover, whereas 8.7 ؎ 1.0% of control cells were multinucleated, 62.4 ؎ 8.8% of the NMHC II-B RNAi-treated cells were multinucleated 72 h after transfection. The RNAitreated cells had increased surface areas and, unlike control cells, lacked actin stress fibers. Treatment of the COS-7 cells with NMHC II-C siRNA decreased NMHC II-C expression to 5.2 ؎ 0.1% compared with the endogenous content of II-C; however, down-regulation of NMHC II-C did not cause increased multinucleation. Immunoblot analysis using a pan-myosin antibody showed that the content of NMHC II-C was less than one-twentieth the amount of NMHC II-B, thereby explaining the lack of response to II-C siRNA. Introducing green fluorescent protein (GFP)-tagged NMHC II isoforms into II-B siRNA-treated cells resulted in reduction of multinucleation from 62.4 ؎ 8.8% to 17.8 ؎ 2.2% using GFP-NMHC II-B, to 29.8 ؎ 7.4% using GFP-NMHC II-A, and to 34.1 ؎ 8.6% using NMHC II-C-GFP. These studies have shown that expression of endogenous NMHC II-C in COS-7 cells is insufficient for normal cytokinesis and that exogenous NMHC II-A and NMHC II-C can, at least partially, rescue the defect in cytokinesis due to the loss of NMHC II-B.Nonmuscle myosin II belongs to the class II myosin superfamily and is expressed in both muscle and nonmuscle cells. Similar to skeletal and smooth muscle myosin II isoforms, it is composed of one pair of heavy chains (200 kDa) and two pairs of light chains (20 and 17 kDa) (1). Three isoforms of nonmuscle myosin heavy chain (NMHC) 1 II, termed NMHC II-A, NMHC II-B, and NMHC II-C, have been identified in mammalian cells (2-5) and are known to be encoded by three different genes, MYH9, MYH10, and MYH14, respectively, in humans (6, 7).The three isoforms are well conserved throughout the whole molecule with a 64 -80% identity in amino acids among the various isoforms (5), suggesting that they might share some cellular functions.On the other hand, studies from a number of laboratories show that the different isoforms have distinct tissue distributions and play different cellular roles (5, 8 -12). For example, murine cardiac myocytes contain NMHC II-B and NMHC II-C and lack NMHC II-A expression. Ablation of NMHC II-A or II-B in mice resulted in markedly different phenotypes, indicating a different role for these isoforms during embryonic development (13-15). In addition, recent studies show that the isoforms have different kinetics when examined by assays of actin-activated MgATPase activity and in vitro motility (16,17).Cytokinesis, a cellu...

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A global emergency due to the COVID-19 pandemic demands various studies related to genes and genomes of the SARS-CoV2. Among other important proteins, the role of accessory proteins are of immense importance in replication, regulation of infections of the coronavirus in the hosts. The largest accessory protein in the SARS-CoV2 genome is ORF3a which modulates the host response to the virus infection and consequently it plays an important role in pathogenesis. In this study, an attempt is made to decipher the conservation of nucleotides, dimers, codons and amino acids in the ORF3a genes across thirty-two genomes of Indian patients. ORF3a gene possesses single and double point mutations in Indian SARS-CoV2 genomes suggesting the change of SARS-CoV2's virulence property in Indian patients. We find that the parental origin of the ORF3a gene over the genomes of SARS-CoV2 and Pangolin-CoV is same from the phylogenetic analysis based on conservation of nucleotides and so on. This study highlights the accumulation of mutation on ORF3a in Indian SARS-CoV2 genomes which may provide the designing therapeutic approach against SARS-CoV2.

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The supramolecular synthon approach has been exploited to design simple salt-based supramolecular gelators derived from a non-steroidal anti-inflammatory drug (NSAID) - naproxen; one such biocompatible anti-inflammatory gelator salt was converted into a topical gel that showed excellent in vivo self-delivery application in treating imiquimod (IMQ)-induced skin inflammation in mice.

We have reported synthesis and vesicular assembly of a novel amphiphilic polyurethane with hydrophobic backbone and hydrophilic pendant carboxylic acid groups which were periodically grafted to the backbone via a tertiary amine group. In aqueous medium the polymer chain adopted a folded conformation which was stabilized by intrachain H-bonding among the urethane groups. Such a model was supported by concentration and solvent-dependent FT-IR, powder XRD, and urea-mediated "denaturation" experiments. Folded polymer chains further formed vesicular assembly which was probed by dynamic light scattering, TEM, AFM, SEM, and fluorescence microscopic studies, and dye encapsulation experiments. pH-dependent DLS and fluorescence microscopic studies revealed stable polymersome in entire tested pH window of 3.5-11.0. Zeta potential measurements showed a negatively charged surface in basic pH while a charge-neutral surface in neutral and acidic pH. MTT assay with CHO cell line indicated good cell viability.