Homogeneous tuples of operators and holomorphic discrete series representation of some classical groups

Let T = (T1....., Tn) be a n-tuple of bounded linear operators on a fixed Hilbert space . H and let φ be a biholomorphic automorphism of Ω, the joint spectrum of T. In this paper, we consider those n-tuples T for which the joint spectrum Ω is of the form G/K, a bounded symmetric domain. Let φ be any biholornorphic automorphism of the domain Ω. Define, phi(T) via a suit­ able functional calculus and call a n-tuple of operators T homogeneous if φ(T) .is simultaneously unitarily equivalent to T for every automorphism φ of Ω. For each homogeneous operator T, let Uφ be a unitary] operator implimenting this equivalence. We obtain a characterisation of all the homogeneous operators Cowen-Douglas class and show that it is possible to choose the unitary Uφ in such a way that the map φ→ Uφ -1 is a unitary representation of the group of of biholomorpic automorphisms of Ω

C-terminal Tail of β-Tubulin and its Role in the Alterations of Dynein Binding Mode

Dynein is a cytoskeletal molecular motor protein that moves along the microtubule (MT) and transports various cellular cargos during its movement. Using standard Molecular Dynamics (MD) simulation, Principle Component Analysis (PCA), and Normal Mode Analysis (NMA) methods, this investigation studied large-scale movements and local interactions of dynein’s Microtubule Binding Domain (MTBD) when bound to tubulin heterodimer subunits. Examination of the interactions between the MTBD segments, and their adjustments in terms of intra- and intermolecular distances at the interfacial area with tubulin heterodimer, particularly at α-H16, β-H18 and β-tubulin C-terminal tail (CTT), was the main focus of this study. The specific intramolecular interactions, electrostatic forces and the salt-bridge residue pairs were shown to be the dominating factors in orchestrating movements of the MTBD and MT interfacial segments in the dynein’s low-high affinity binding modes. Important interactions included β-Glu447 and β-Glu449 (CTT) with Arg3469 (MTBD-H6), Lys3472 (MTBD-H6-H7 loop) and Lys3479 (MTBD-H7); β-Glu449 with Lys3384 (MTBD-H8), Lys3386 and His3387 (MTBD-H1). The structural and precise position, orientation, and functional effects of the CTTs on the MT-MTBD, within reasonable cut-off distance for non-bonding interactions and under physiological conditions, are unavailable from the previous studies. The absence of the residues in the highly flexible MT-CTTs in the experimentally solved structures is perhaps in some cases due to insufficient data from density maps, but these segments are crucial in protein binding. The presented work contributes to the information useful for the MT-MTBD structure refinement

A sight record of Rhesus Macaque <i>Macaca mulatta</i> (Primates: Cercopithecidae) in Karnataka, India

The Rhesus Macaque Macaca mulatta is one of the most widely distributed macaques belonging to the order Primates. It is found in northern, central and northeastern India as well as Central and South East Asia. However, there has been no record of this species being found in the state of Karnataka, India. This note presents the first sight record of this species in Karnataka, India

Occurrence of philometra lateolabracis (philometridae) in the subcutaneous caudal fin region of sciaenid fishes of Bay of Bengal Large Marine Ecosystem (BOBLME), Tamil Nadu (India)

Present study consists the prevalence of philometrid nematode, Philometra lateolabracis infections in two species of Sciaenid fishes along the Madras coastal water, Bay of Bengal during December, 2008 to July, 2012. Out of total 295 sciaenid fishes, examined, Otolithes ruber and Pennahia macrophthalmus showed 70% & 32.5% of parasitic prevalence on the subcutaneous region on caudal fins. The number of parasitic worms per fish varied from 1 to 7 with an average of 3.18±1.64. Parasites length varies from 5-16 mm with an average of 11.18±4.62 mm. The minimum and maximum sizes and weight of Sciaenid fishes were caught from Kasimedu landing centre (Chennai) during October-December, 2012 varied from180-287 mm and weight 120-245 gm respectively

Not Available

Not AvailablePresent study consists the prevalence of philometrid nematode, Philometra lateolabracis infections in two species of Sciaenid fishes along the Madras coastal water, Bay of Bengal during December, 2008 to July, 2012. Out of total 295 sciaenid fishes, examined, Otolithes ruber and Pennahia macrophthalmus showed 70% & 32.5% of parasitic prevalence on the subcutaneous region on caudal fins. The number of parasitic worms per fish varied from 1 to 7 with an average of 3.18±1.64. Parasites length varies from 5-16 mm with an average of 11.18±4.62 mm. The minimum and maximum sizes and weight of Sciaenid fishes were caught from Kasimedu landing centre (Chennai) during October-December, 2012 varied from180-287 mm and weight 120-245 gm respectively.Not Availabl

Glutamylation imbalance impairs the molecular architecture of the photoreceptor cilium.

Microtubules, composed of conserved α/β-tubulin dimers, undergo complex post-translational modifications (PTMs) that fine-tune their properties and interactions with other proteins. Cilia exhibit several tubulin PTMs, such as polyglutamylation, polyglycylation, detyrosination, and acetylation, with functions that are not fully understood. Mutations in AGBL5, which encodes the deglutamylating enzyme CCP5, have been linked to retinitis pigmentosa, suggesting that altered polyglutamylation may cause photoreceptor cell degeneration, though the underlying mechanisms are unclear. Using super-resolution ultrastructure expansion microscopy (U-ExM) in mouse and human photoreceptor cells, we observed that most tubulin PTMs accumulate at the connecting cilium that links outer and inner photoreceptor segments. Mouse models with increased glutamylation (Ccp5 &lt;sup&gt;-/-&lt;/sup&gt; and Ccp1-/-) or loss of tubulin acetylation (Atat1-/-) showed that aberrant glutamylation, but not acetylation loss, disrupts outer segment architecture. This disruption includes exacerbation of the connecting cilium, loss of the bulge region, and destabilization of the distal axoneme. Additionally, we found significant impairment in tubulin glycylation, as well as reduced levels of intraflagellar transport proteins and of retinitis pigmentosa-associated protein RPGR. Our findings indicate that proper glutamylation levels are crucial for maintaining the molecular architecture of the photoreceptor cilium

Knocking Out Multiple Genes in Cultured Primary Neurons to Study Tubulin Posttranslational Modifications

International audienceMicrotubules, as integral part of the eukaryotic cytoskeleton, exert numerous essential functions in cells. A mechanism to control these diverse functions are the posttranslational modifications of tubulin. Despite being known for decades, relatively little insight into the cellular functions of these modifications has been gained so far. The discovery of tubulin-modifying enzymes and a growing number of available knockout mice now allow working with primary cells from those mouse models to address biological functions and molecular mechanisms behind those modifications. However, a number of those mouse models show either lethality or sterility, making it difficult to impossible to obtain a sufficient number of animals for a systematic study with primary cells. Moreover, many of those modifications are controlled by several redundant enzymes, and it is often necessary to knock out several enzymes in parallel to obtain a significant change in a given tubulin modification. Here we describe a method to generate primary cells with combinatorial knockout genotypes using conditional knockout mice. The conditional alleles are converted into knockout in the cultured primary cells by transduction with a lentivirus encoding cre-recombinase. This approach has allowed us to knock out the two main brain deglutamylases in mouse primary neurons, which leads to strongly increased polyglutamylation in these cells. Our method can be applied to measure different cellular processes, such as axonal transport, for which it can be combined with the expression of different fluorescent reporters to label intracellular proteins. Using a panel of conditional knockout mice, our method can further be applied to study the functions of a variety of tubulin modifications that require simultaneous knockout of multiple genes