The Atypical Calpains: Evolutionary Analyses and Roles in Caenorhabditis elegans Cellular Degeneration

The calpains are physiologically important Ca2+-activated regulatory proteases, which are divided into typical or atypical sub-families based on constituent domains. Both sub-families are present in mammals, but our understanding of calpain function is based primarily on typical sub-family members. Here, we take advantage of the model organism Caenorhabditis elegans, which expresses only atypical calpains, to extend our knowledge of the phylogenetic evolution and function of calpains. We provide evidence that a typical human calpain protein with a penta EF hand, detected using custom profile hidden Markov models, is conserved in ancient metazoans and a divergent clade. These analyses also provide evidence for the lineage-specific loss of typical calpain genes in C. elegans and Ciona, and they reveal that many calpain-like genes lack an intact catalytic triad. Given the association between the dysregulation of typical calpains and human degenerative pathologies, we explored the phenotypes, expression profiles, and consequences of inappropriate reduction or activation of C. elegans atypical calpains. These studies show that the atypical calpain gene, clp-1, contributes to muscle degeneration and reveal that clp-1 activity is sensitive to genetic manipulation of [Ca2+]i. We show that CLP-1 localizes to sarcomeric sub-structures, but is excluded from dense bodies (Z-disks). We find that the muscle degeneration observed in a C. elegans model of dystrophin-based muscular dystrophy can be suppressed by clp-1 inactivation and that nemadipine-A inhibition of the EGL-19 calcium channel reveals that Ca2+ dysfunction underlies the C. elegans MyoD model of myopathy. Taken together, our analyses highlight the roles of calcium dysregulation and CLP-1 in muscle myopathies and suggest that the atypical calpains could retain conserved roles in myofilament turnover

Laser-induced rotation and cooling of a trapped microgyroscope in vacuum

This work was supported by the UK Engineering and Physical Sciences Research Council (EPSRC grant numbers: EP/J01771X/1 and EP/G061688/1)Quantum state preparation of mesoscopic objects is a powerful playground for the elucidation of many physical principles. The field of cavity optomechanics aims to create these states through laser cooling and by minimizing state decoherence. Here we demonstrate simultaneous optical trapping and rotation of a birefringent microparticle in vacuum using a circularly polarized trapping laser beam—a microgyroscope. We show stable rotation rates up to 5 MHz. Coupling between the rotational and translational degrees of freedom of the trapped microgyroscope leads to the observation of positional stabilization in effect cooling the particle to 40 K. We attribute this cooling to the interaction between the gyroscopic directional stabilization and the optical trapping field.Publisher PDFPeer reviewe

Oral Vaccine Delivery: The Coming Age of Particulate Vaccines to Elicit Mucosal Immunity

With the evolution of different challenging diseases, there is an urgent need of vaccine development against them to save millions of lives around the world. Particlulate delivery system plays an important role by acting as self-adjuvant in form of particles and thus assisting the immunogenicity of vaccines. Particulate vaccines have shown to have improved uptake by antigen presenting cells as compared to the soluble antigen. Traditional injectable vaccines are generally poor inducers of mucosal immunity and are therefore less effective against infections at the mucosal site. Mucosal vaccines have been reported to provide additional secretory antibody mediated protection at the mucosal site of entry of the pathogen. In this chapter, we discuss the benefits of particulate drug delivery systems for oral delivery, the role of immune system in the gut, and a case study ofa novel particulate vaccine formulated into oral dissolving film for immunization via the buccal route. Key formulation components, process parameters and their biophysical characterizations have been discussed as well