LIS1 and NudE induce a persistent dynein force-producing state.

Cytoplasmic dynein is responsible for many aspects of cellular and subcellular movement. LIS1, NudE, and NudEL are dynein interactors initially implicated in brain developmental disease but now known to be required in cell migration, nuclear, centrosomal, and microtubule transport, mitosis, and growth cone motility. Identification of a specific role for these proteins in cytoplasmic dynein motor regulation has remained elusive. We find that NudE stably recruits LIS1 to the dynein holoenzyme molecule, where LIS1 interacts with the motor domain during the prepowerstroke state of the dynein crossbridge cycle. NudE abrogates dynein force production, whereas LIS1 alone or with NudE induces a persistent-force dynein state that improves ensemble function of multiple dyneins for transport under high-load conditions. These results likely explain the requirement for LIS1 and NudE in the transport of nuclei, centrosomes, chromosomes, and the microtubule cytoskeleton as well as the particular sensitivity of migrating neurons to reduced LIS1 expression.

Computer simulation reveals the effect of severing enzymes on dynamic and stabilized microtubules.

Microtubule (MT) severing enzymes Katanin and Spastin cut the MT into smaller fragments and are being studied extensively usingin-vitroexperiments due to their crucial role in different cancers and neurodevelopmental disorders. It has been reported that the severing enzymes are either involved in increasing or decreasing the tubulin mass. Currently, there are a few analytical and computational models for MT amplification and severing. However, these models do not capture the action of MT severing explicitly, as these are based on partial differential equations in one dimension. On the other hand, a few discrete lattice-based models were used earlier to understand the activity of severing enzymes only on stabilized MTs. Hence, in this study, discrete lattice-based Monte Carlo models that included MT dynamics and severing enzyme activity have been developed to understand the effect of severing enzymes on tubulin mass, MT number, and MT length. It was found that the action of severing enzyme reduces average MT length while increasing their number; however, the total tubulin mass can decrease or increase depending on the concentration of GMPCPP (Guanylyl-(α,ß)-methylene-diphosphonate)-which is a slowly hydrolyzable analogue of GTP (Guanosine triphosphate). Further, relative tubulin mass also depends on the detachment ratio of GTP/GMPCPP and Guanosine diphosphate tubulin dimers and the binding energies of tubulin dimers covered by the severing enzyme.

Luteinizing hormone ß-subunit deficiency: Report of a novel LHB likely pathogenic variant and a systematic review of the published literature.

CONTEXT: Selective deficiency of ß-subunit of luteinizing hormone (LHB) is a rare disease with scarce data on its characteristics. OBJECTIVES: To describe a male with LHB deficiency and systematically review the literature. DESIGN AND PATIENTS: Description of a male patient with LHB deficiency and a systematic review of LHB deficiency patients published to date (10 males and 3 females) as per PRISMA guidelines. RESULTS: A 36-year-old Asian Indian male presented with infertility. On evaluation, he had sexual maturity of Tanner's stage 3, low testosterone (0.23 ng/ml), low LH (0.44 mIU/ml), high follicle-stimulating hormone (FSH, 22.4 mIU/ml), and a novel homozygous missense likely pathogenic variant (p.Cys46Arg) in LHB. In the molecular dynamics simulation study, this variant interferes with heterodimerization of alpha-beta subunits. Eleven males with pathogenic variants in LHB reported to date, presented at a median age of 29 (17-38) years, most commonly with delayed puberty. Clinical and biochemical profiles were similar to those of our patient. In the majority, testosterone monotherapy modestly increased testicular volume whereas human chorionic gonadotropin (hCG) monotherapy also improved spermatogenesis. In females, oligomenorrhoea after spontaneous menarche was the most common manifestation. Ten pathogenic/likely pathogenic variants (three in-frame deletions, three missense, two splice-site, one nonsense, and one frameshift variants) have been reported in nine index patients. CONCLUSION: We report a novel likely pathogenic LHB variant in an Asian Indian patient. The typical phenotype in male patients with LHB deficiency is delayed puberty with low testosterone, low LH, and normal to high FSH and hCG monotherapy being the best therapeutic option.

Side-chain cleavage enzyme deficiency: Systematic review and case series.

OBJECTIVE: P450 side-chain cleavage deficiency (SCCD) patients present with primary adrenal insufficiency (PAI) with or without undervirilized external genitalia. The distinction between classic and nonclassic steroidogenic acute regulatory protein deficiency has been described, whereas in SCCD is unclear. The data on gonadal function and its correlation with SCCD genotype has not been studied. We describe our experience and perform a systematic review of genetically proven SCCD patients to determine the distinct phenotypic and genotypic characteristics of 46,XY SCCD patients with typical male external genitalia (SCCD-TMG) and atypical (SCCD-AG) external genitalia. DESIGN, PATIENTS AND MEASUREMENTS: Retrospective review of three genetically proven SCCD patients from our centre and per-patient data analysis from a systematic review of 52 probands was performed. SCCD-TMG (n = 19) was defined as external genitalia of Sinnecker score 1 with 46,XY  karyotype; the rest (Sinnecker 2-5) were classified as SCCD-AG (n = 15). RESULTS: We report two new Indian cases of SCCD with three novel likely pathogenic variants and pubertal follow-up of a previously reported patient. In systematic review, age at diagnosis of PAI and elevated renin were not different between 46,XY  SCCD-TMG (n = 19) and SCCD-AG (n = 15), whereas spontaneous puberty (9/9 vs. 0/3, p = .0045), normal prepubertal (5/5 vs. 6/6, p = .002), pubertal gonadotropins (2/9 vs. 0/3, p = 1) and normal pubertal testosterone (9/11 vs. 0/3, p = .027) were more common in SCCD-TMG. Testicular adrenal rest tumours were exclusive to SCCD-TMG (n = 4). SCCD-TMG was associated with four particular genotypes [monoallelic p.Glu314Lys with another deleterious variant on the second allele (p.Glu314Lys/X-CHS: X-compound heterozygous state), biallelic p.Arg451Trp, p.Phe215Ser/p.Arg232Ter and monoallelic p.Val79Ile]. 46,XX SCCD  patients with p.Glu314Lys/X-CHS also had normal gonadotropins with spontaneous puberty. CONCLUSION: SCCD-TMG is associated with four specific genotypes and distinct gonadal characteristics from SCCD-AG with overlapping features of PAI.

Genotypic Spectrum and its Correlation with Alopecia and Clinical Response in Hereditary Vitamin D Resistant Rickets: Our Experience and Systematic Review.

Alopecia in hereditary vitamin D resistant rickets (HVDRR) has some correlation with severe rickets and poor overall response. However, these observations are based on small series. Hence, we aim to assess the genotypic spectrum of HVDRR and its correlation with alopecia and clinical response. Seven genetically-proven HVDDR patients from five unrelated families and 119 probands from systematic review were analysed retrospectively for phenotypic and genotypic data and overall response to therapy. In our cohort mean age at rickets onset was 12 (± 3.4) months. Alopecia was present in all patients but one. All patients had poor overall response to oral high-dose calcium and calcitriol and most required intravenous calcium. Genetic analyses revealed four novel variants. On systematic review, alopecia was present in majority (81.5%) and preceded the onset of rickets. Patients with alopecia had higher serum calcium (7.6 vs.6.9 mg/dl, p = 0.008), lower 1, 25(OH)2 D (200 vs.320 pg/ml, p = 0.03) and similar overall response to oral therapy (28.7% vs. 35.3%, p = 0.56). Alopecia was present in 51.4% of non-truncating (NT) ligand-binding domain (LBD) variants, whereas it was universal in truncating LBD and all DNA binding-domain (DBD) variants. Overall response to oral therapy was highest in LBD-NT (46.4%) as compared to 7.6% in LBD-truncating and 19% in DBD-NT variants. Among LBD-NT variants, those affecting RXR heterodimerization, but not those affecting ligand affinity, were associated with alopecia. Both alopecia and overall response have genotypic correlation. Age at diagnosis and overall response to oral therapy were similar between patients with and without alopecia in genetically proven HVDRR.

Cargo transport properties are enhanced by cylindrical microtubule geometry and elliptical contact zone on cargo surface.

Molecular motors are responsible for carrying cellular transport of various membranous vesicles or organelles along cytoskeletal tracks. Transport of cellular cargos require high forces that are generated by motors working in groups. Hence, the properties of cargo transport can be modulated by varying various parameters such as cargo size and shape, microtubule geometry, motor number and their arrangement on cargo surface. Only those motors which are present in the contact zone on cargo surface have potential to bind to microtubule. Although earlier studies revealed the importance of cargo size, total motors attached to microtubule and their arrangement on cargo transport, yet how the contact zone influences binding of motors to microtubule largely remains unexplored. Here, it has been shown that contact zone is elliptical in shape for a spherical cargo and increases with cargo size for Kinesin-1 motors. To further understand the combined effect of elliptical contact zone and microtubule geometry on cargo transport, 3D mean-field model with uniform and clustered arrangement of motors for different cargo sizes and motor number has been used. Our findings indicate that cylindrical microtubule geometry maximizes the microtubule-bound motors which enhances the runlength and velocity of cargo transport. Our results show that microtubule-bound motors decrease with cargo size for uniform arrangement of motors on cargo thus decreasing its runlength and velocity, whereas in clustered arrangement, the number of microtubule-bound motors increase with cargo size which leads to increase in runlength and velocity.

Sliding of motor tails on cargo surface due to drift and diffusion affects their team arrangement and collective transport.

Kinesin is a microtubule-associated motor protein which works in teams to carry the cellular cargo transport. Lipid rafts on membranous cargos reorganize, causing the motors present in these areas to physically cluster. Unregulated clustering of motors leads to diseases such as Leishmaniasis, Newmann-Pick disease, etc. Variousin-vitroand computational studies have reported improved cargo velocity and travel distance of a fluid cargo as compared to a rigid cargo. However, only cargo velocity increases with increase in membrane fluidity of a fluid cargo. Thermal and motor forces acting tangentially on a cargo generate random torque and motor torque respectively, leading to cargo rotation and motor tail sliding on cargo surface. However, it is unknown which of these forces/torques play a crucial role in improving the transport properties. Here, we use computational models that incorporate random torque, motor torque, and combination of both random and motor torques to understand how they influence the clustering of Kinesin motors on cargo surface due to drift and diffusion of their tails. These studies were performed at varying tail diffusivity to understand their effect on clustering of tails in dispersed and clustered arrangement. We find that in dispersed arrangement, random torque does not cause clustering, whereas motor torque is crucial for clustering of tails on cargo surface, and tails sliding due to both random and motor torques have fastest cargo transport and maximum cooperativity. In clustered arrangement, tails slide to form a broad and steady cluster whose size increases with tail diffusivity resulting in decreased cargo runlength, velocity and cooperativity. These findings suggest that increased tail diffusivity negatively impacts the cluster and cargo transport of tails in the clustered arrangement, whereas it aids physical clustering of tails and cargo transport in dispersed arrangement.

17ß hydroxysteroid dehydrogenase 3 deficiency in 46,XY disorders of sex development: Our experience and a gender role-focused systematic review.

OBJECTIVES: To describe Asian Indian patients with 17ß hydroxysteroid dehydrogenase 3 (17ßHSD3) deficiency and to perform a systematic review to determine the factors influencing gender role in 46,XY disorder of sex development (DSD) due to 17ßHSD3 deficiency. PATIENTS AND DESIGN: We present the phenotypic and genotypic data of 10 patients (9 probands and 1 affected family member) with 17ßHSD3 deficiency from our 46,XY DSD cohort (N = 150; Western India) and a systematic review of 152 probands with genetically proven, index 17ßHSD3 deficiency patients from the world literature to identify the determinants of gender role. RESULTS: 17ßHSD3 deficiency was the third most common (6%) cause of non-dysgenetic 46,XY DSD in our cohort. Five patients each had prepubertal (atypical genitalia) and pubertal (primary amenorrhoea) presentations. Six patients were initially reared as female of whom two (one each in prepubertal and pubertal age) changed their gender role. Ten pathogenic molecular variants (six novel) were observed. In the systematic review, initial male sex of rearing was uncommon (10.5%) and was associated with atypical genitalia, higher testosterone/androstenedione (T/A) ratio and Asian origin. Gender role change to male was seen in 10.3% of patients with initial female sex of rearing and was associated with Asian origin but unrelated to pubertal androgens or molecular variant severity. It has not been reported in patients of European origin. CONCLUSIONS: We report the first Indian case series of 17ßHSD3 deficiency, the third most common cause of 46,XY DSD, with six novel molecular variants. Distinct geographical differences in the frequency of initial male sex of rearing and gender role change to male in those initially reared as females in 17ßHSD3 deficiency were noted which needs further evaluation for the underlying molecular mechanisms.

Reversible association with motor proteins (RAMP): A streptavidin-based method to manipulate organelle positioning.

We report the development and characterization of a method, named reversible association with motor proteins (RAMP), for manipulation of organelle positioning within the cytoplasm. RAMP consists of coexpressing in cultured cells (i) an organellar protein fused to the streptavidin-binding peptide (SBP) and (ii) motor, neck, and coiled-coil domains from a plus-end-directed or minus-end-directed kinesin fused to streptavidin. The SBP-streptavidin interaction drives accumulation of organelles at the plus or minus end of microtubules, respectively. Importantly, competition of the streptavidin-SBP interaction by the addition of biotin to the culture medium rapidly dissociates the motor construct from the organelle, allowing restoration of normal patterns of organelle transport and distribution. A distinctive feature of this method is that organelles initially accumulate at either end of the microtubule network in the initial state and are subsequently released from this accumulation, allowing analyses of the movement of a synchronized population of organelles by endogenous motors.

GNRH1 Variants in Congenital Hypogonadotropic Hypogonadism: Single-Center Experience and Systematic Literature Review.

OBJECTIVE: As GNRH1 genotype-phenotype correlation in CHH is not well studied, we aim to describe the GNRH1 variants in our CHH cohort and present a systematic review as well as genotype-phenotype analysis of all mutation-positive cases reported in the world literature. DESIGN: This is a retrospective study of GNRH1 mutation-positive patients from a western Indian center. PRISMA guidelines-based PubMed search of the published literature of all GNRH1 mutation-positive patients was conducted. SETTING: This study was conducted in an academic medical center. PATIENT(S): This study included 2 probands from our cohort and 19 probands from the world literature. MAIN OUTCOME MEASURE(S): Demographic details, clinical presentation, biochemistry, imaging, treatment details, and genotypic data were recorded. RESULT(S): Two probands in our cohort carried two novel pathogenic biallelic GNRH1 variants (p.Glu24Leu, c.238-2A>G). Both had a severe reproductive phenotype. We report successful gonadotropin therapy and fertility in 1 proband. We included 19 probands from 12 studies after the literature review. Ten CHH probands (inclusive 2 from this study) with biallelic GNRH1 variants had severe reproductive phenotype, low gonadotropin levels, low/normal prolactin, normal pituitary imaging, and no extra-reproductive phenotype. Of seven biallelic variants reported, three were frameshift, two were splice-site, and two were missense mutations. All of them were pathogenic/likely pathogenic without oligogenicity. Of seven monoallelic GNRH1 variants reported in 11 probands, 4 had nonreproductive phenotype, 3 were benign/likely benign, and 4 were oligogenic. CONCLUSION(S): GNRH1 biallelic variants lead to severe reproductive phenotype, with low gonadotropin levels without nonreproductive features or oligogenicity. However, the role of GNRH1 monoallelic variants in CHH pathophysiology for reported variants remains questionable.

Computational study of interactions of anti-cancer drug eribulin with human tubulin isotypes.

Microtubules (MTs) are widely targeted for the treatment of various types of cancer due to their essential role in cell division. MTs are polymers made of αß-tubulin heterodimers. These α- and ß-tubulins have 8 and 10 different isotypes, respectively. It is known that a few tubulin isotypes have anti-cancer drug resistance properties, especially ßIII, which shows poor sensitivity to many potent anti-cancer drugs such as eribulin. However, the molecular-level understanding of drug-resistance due to tubulin isotype variation is poorly understood. This paper presents the study of differential binding affinities of different tubulin isotypes with the potent anti-cancer drug eribulin. Eribulin (MT destabilizer) binds at the inter-dimer interface of MTs near the vinca site and induces a lattice deformation, which results in catastrophic events in MT dynamics. In this study, sequence analysis has been done throughway and the binding sites and based on that 2α-tubulin isotypes (αI and αVIII) and 7ß tubulin isotypes (ßI, ßIIa, ßIII, ßIVa, ßVI, ßVII and ßVIII) were selected. In total, 14 combinations were prepared after building homology models of these selected isotypes. Molecular docking and molecular dynamics simulations were performed to deeply understand the binding mode of eribulin at different MT compositions. RMSD, RMSF, radius of gyration, SASA, ligand-protein interactions, and calculations of binding free energy were performed to investigate the eribulin binding variations to tubulin isotypes and it was found that αIßII showed the maximum binding affinity among all 14 systems to eribulin. The ßIII-tubulin isotype, which shows low sensitivity to eribulin in experimental results, had the least binding affinity in the system αVIIIßIII complex and the average binding affinity in the system αIßIII among all 14 systems. Additionally, we performed steered MD simulations and DynDom analysis of the systems with the lowest binding energy (αIßII) and the highest binding energy (αVIIIßIII) and extracted force, displacement, and H-bonding profiles during the pulling simulations to get a better insight.

Expanding genetic spectrum and discriminatory role of steroid profiling by LC-MS/MS in 11ß-hydroxylase deficiency.

OBJECTIVE: To report clinical, hormonal and structural effects of CYP11B1 pathogenic variations in Indian patients with 11ß-hydroxylase deficiency (11ßOHD) and find hormonal criteria that accurately distinguish 11ßOHD from 21α-hydroxylase deficiency (21OHD). DESIGN: Retrospective record review of genetically diagnosed patients with 11ßOHD. PATIENTS AND MEASUREMENTS: Clinical features, hormonal parameters at diagnosis (by immunoassay) and recent follow-up of 13 genetically proven 11ßOHD patients managed at our centre were retrospectively reviewed. ACTH-stimulated serum adrenal steroids (measured by LC-MS/MS) of 11ßOHD were compared with those of simple virilizing and non-classic 21OHD. Structural analysis of the observed pathogenic variations was performed by computational modelling. RESULTS: Nine (four females) and four (all females) patients had classic and non-classic disease, respectively. All 11ßOHD patients had elevated ACTH-stimulated serum 11-deoxycortisol (26.5-342.7 nmol/L) whereas none had elevated serum 17-hydroxyprogesterone (4.2-21.2 nmol/L); both hormonal parameters distinguished 11ßOHD from 21OHD with 100% accuracy. ACTH-stimulated serum cortisol, but not 11-deoxycortisol, clearly distinguished classic (<70 nmol/L) from non-classic (>160 nmol/L) disease. Thirteen (eight novel, two recurrent) pathogenic variants were observed. Only missense mutations were observed among patients with non-classic disease. Computational modelling predicted the possible affection of enzyme structure and function for all the observed missense mutations. CONCLUSIONS: This first Indian study describes 13 11ßOHD patients, including four with the rarer non-classic variant. A total of eight novel pathogenic variants were identified in our study, highlighting regional genetic heterogeneity. Measurement of ACTH-stimulated adrenal steroids by LC-MS/MS will help avoid the misdiagnosis of 11ßOHD as 21OHD and has potential to distinguish classic from non-classic 11ßOHD.

Structure-based virtual screening, molecular docking, ADMET and molecular simulations to develop benzoxaborole analogs as potential inhibitor against Leishmania donovani trypanothione reductase.

Visceral leishmaniasis (VL) is the most fatal form of leishmaniasis and it affects 70 countries worldwide. Increasing drug resistant for antileishmanial drugs such as miltefosine, sodium stibogluconate and pentamidine has been reported in the VL endemic region. Amphotericin B has shown potential antileishmanial activity in different formulations but its cost of treatment and associated nephrotoxicity have limited its use by affected people living in the endemic zone. To control the VL infection in the affected countries, it is necessary to develop new antileishmanial compounds with high efficacy and negligible toxicity. Computer aided programs such as binding free energy estimation; ADMET prediction and molecular dynamics simulation can be used to investigate novel antileishmanial molecules in shorter duration. To develop antileishmanial lead molecule, we performed standard precision (SP) docking for 1160 benzoxaborole analogs along with reference inhibitors against trypanothione reductase of Leishmania parasite. Furthermore, extra precision (XP) docking, ADMET prediction, prime MM-GBSA was conducted over 115 ligands, showing better docking score than reference inhibitors to get potential antileishmanial compounds. Simultaneously, area under the curve (AUC) was estimated using ROC plot to validate the SP and XP docking protocol. Later on, two benzoxaborole analogs with best MM-GBSA ΔG-bind were subjected to molecular simulation and docking confirmation to ensure the ligand interaction with TR. The presented drug discovery based on computational study confirms that BOB27 can be used as a potential drug candidate and warrants further experimental investigation to fight against VL in endemic areas.

The Effect of Temperature on Microtubule-Based Transport by Cytoplasmic Dynein and Kinesin-1 Motors.

Cytoplasmic dynein and kinesin are both microtubule-based molecular motors but are structurally and evolutionarily unrelated. Under standard conditions, both move with comparable unloaded velocities toward either the microtubule minus (dynein) or plus (most kinesins) end. This similarity is important because it is often implicitly incorporated into models that examine the balance of cargo fluxes in cells and into models of the bidirectional motility of individual cargos. We examined whether this similarity is a robust feature, and specifically whether it persists across the biologically relevant temperature range. The velocity of mammalian cytoplasmic dynein, but not of mammalian kinesin-1, exhibited a break from simple Arrhenius behavior below 15°C-just above the restrictive temperature of mammalian fast axonal transport. In contrast, the velocity of yeast cytoplasmic dynein showed a break from Arrhenius behavior at a lower temperature (∼8°C). Our studies implicate cytoplasmic dynein as a more thermally tunable motor and therefore a potential thermal regulator of microtubule-based transport. Our theoretical analysis further suggests that motor velocity changes can lead to qualitative changes in individual cargo motion and hence net intracellular cargo fluxes. We propose that temperature can potentially be used as a noninvasive probe of intracellular transport.

Thalidomide (5HPP-33) suppresses microtubule dynamics and depolymerizes the microtubule network by binding at the vinblastine binding site on tubulin.

Thalidomides were initially thought to be broad-range drugs specifically for curing insomnia and relieving morning sickness in pregnant women. However, its use was discontinued because of a major drawback of causing teratogenicity. In this study, we found that a thalidomide derivative, 5-hydroxy-2-(2,6-diisopropylphenyl)-1H-isoindole-1,3-dione (5HPP-33), inhibited the proliferation of MCF-7 with a half-maximal inhibitory concentration of 4.5 ± 0.4 µM. 5HPP-33 depolymerized microtubules and inhibited the reassembly of cold-depolymerized microtubules in MCF-7 cells. Using time-lapse imaging, the effect of 5HPP-33 on the dynamics of individual microtubules in live MCF-7 cells was analyzed. 5HPP-33 (5 µM) decreased the rates of growth and shortening excursions by 34 and 33%, respectively, and increased the time microtubules spent in the pause state by 92% as compared to that of the vehicle-treated MCF-7 cells. 5HPP-33 (5 µM) reduced the dynamicity of microtubules by 62% compared to the control. 5HPP-33 treatment reduced the distance between the two poles of a bipolar spindle, induced multipolarity in some of the treated cells, and blocked cells at mitosis. In vitro, 5HPP-33 bound to tubulin with a weak affinity. Vinblastine inhibited the binding of 5HPP-33 to tubulin, and 5HPP-33 inhibited the binding of BODIPY FL-vinblastine to tubulin. Further, a molecular docking analysis suggested that 5HPP-33 shares its binding site on tubulin with vinblastine. The results provided significant insight into the antimitotic mechanism of action of 5HPP-33 and also suggest a possible mechanism for the teratogenicity of thalidomides.

Mechanical stochastic tug-of-war models cannot explain bidirectional lipid-droplet transport.

Intracellular transport via the microtubule motors kinesin and dynein plays an important role in maintaining cell structure and function. Often, multiple kinesin or dynein motors move the same cargo. Their collective function depends critically on the single motors' detachment kinetics under load, which we experimentally measure here. This experimental constraint--combined with other experimentally determined parameters--is then incorporated into theoretical stochastic and mean-field models. Comparison of modeling results and in vitro data shows good agreement for the stochastic, but not mean-field, model. Many cargos in vivo move bidirectionally, frequently reversing course. Because both kinesin and dynein are present on the cargos, one popular hypothesis explaining the frequent reversals is that the opposite-polarity motors engage in unregulated stochastic tugs-of-war. Then, the cargos' motion can be explained entirely by the outcome of these opposite-motor competitions. Here, we use fully calibrated stochastic and mean-field models to test the tug-of-war hypothesis. Neither model agrees well with our in vivo data, suggesting that, in addition to inevitable tugs-of-war between opposite motors, there is an additional level of regulation not included in the models.

Coordination, cooperation, competition, crowding and congestion of molecular motors: Theoretical models and computer simulations.

Cytoskeletal motor proteins are biological nanomachines that convert chemical energy into mechanical work to carry out various functions such as cell division, cell motility, cargo transport, muscle contraction, beating of cilia and flagella, and ciliogenesis. Most of these processes are driven by the collective operation of several motors in the crowded viscous intracellular environment. Imaging and manipulation of the motors with powerful experimental probes have been complemented by mathematical analysis and computer simulations of the corresponding theoretical models. In this article, we illustrate some of the key theoretical approaches used to understand how coordination, cooperation and competition of multiple motors in the crowded intra-cellular environment drive the processes that are essential for biological function of a cell. In spite of the focus on theory, experimentalists will also find this article as an useful summary of the progress made so far in understanding multiple motor systems.

Far-UVC (222 nm) irradiation effectively inactivates ssRNA, dsRNA, ssDNA, and dsDNA viruses as compared to germicidal UVC (254 nm).

Ultraviolet-C (UVC) irradiation is being used as an effective approach for the disinfection of pathogenic viruses present in air, surfaces, and water. Recently, far-UVC radiation (222 nm) emitted by KrCl* (krypton-chloride) excimer lamps have been recommended for disinfecting high-risk public spaces to reduce the presence and transmission of infectious viruses owing to limited human health exposure risks as compared to germicidal UVC (254 nm). In this study, the UVC inactivation performances of individual filtered KrCl* excimer lamp (222 nm) and germicidal UVC lamp (254 nm) were determined against four viruses, bacteriophages MS2, Phi6, M13, and T4, having different genome compositions (ssRNA, dsRNA, ssDNA and dsDNA, respectively) and shapes (i.e., spherical (Phi6), linear (M13), and icosahedral (MS2 and T4)). Here, the disinfection efficacies of filtered KrCl* excimer lamp (222 nm) and germicidal UVC lamp (254 nm) were evaluated for highly concentrated virus droplets that mimic the virus-laden droplets released from the infected person and deposited on surfaces as fomites. Filtered KrCl* excimer (222 nm) showed significantly better inactivation against all viruses having different genome compositions and structures compared to germicidal UVC (254 nm). The obtained sensitivity against the filtered KrCl* excimer (222 nm) was found to be in the order, T4 > M13 > Phi6 > MS2 whereas for the germicidal UVC (254 nm) it was T4 > M13 > MS2 > Phi6. These results provide a strong basis to promote the use of filtered KrCl* excimer lamps (222 nm) in disinfecting contagious viruses and to limit the associated disease spread in public places and other high-risk areas.

46,XX aromatase deficiency: A single-center experience with the varied spectrum and recurrent variants, and a systematic review of hormonal parameters.

BACKGROUND: Aromatase deficiency is a rare disorder, with only a few cases reported in India. We describe a single-center experience in western India, with a systematic review of genetically proven 46,XX aromatase deficiency patients to evaluate hormonal parameters. METHODS: Retrospective review of case records, collating phenotypic and genotypic data and molecular modeling. Systematic review of 46,XX aromatase deficiency, analyzing data on gonadotropins, estrogen and androgens. RESULTS: In the seven patients from our center, presentation was frequent in childhood or adolescence (4/7: delayed puberty or hyperandrogenism), with maternal virilization (4/7), predominance of Prader III/IV (5/7), and initial rearing as females (6/7). Three patients had hypoplastic ovaries. One patient had spontaneous regular menses. We report three novel (p.Arg115Pro, p.Arg192Pro, and c.145+1_145+4delins) and two recurrent variants (p.Val370Met, and c.145+1_145+4delins) in western and northern India, respectively. On systematic review (n=43), gonadotropins were elevated (FSH>LH) across ages (except preterm infants), androgens were elevated in about one-third of cases during childhood and puberty, and estradiol was lower than in controls in mini-puberty and puberty. Spontaneous thelarche and streak ovaries were significantly more frequent in patients with non-truncating and truncating variants, respectively. CONCLUSION: We report uncommon presentations with possible founder variants, and highlight hormonal parameters across ages. Serum FSH levels were elevated except in preterms, and can be used as a diagnostic marker.

Genotype and Phenotype of 21-Hydroxylase Deficiency: A Single Center Experience from Western India.

OBJECTIVE: To describe the genotype-phenotype characteristics of patients with 21-hydroxylase deficiency from western India and ascertain the prevalence of various phenotypes of 21-hydroxylase deficiency. METHODS: Patients with 21-hydroxylase deficiency, diagnosed clinically and biochemically, were prospectively enrolled and classified into salt wasting (SW), simple virilizing (SV), and non-classic (NC) phenotypes and were subjected to genetic testing of CYP21A2 by targeted sequencing and multiplex ligation-dependent probe amplification (MLPA). RESULTS: Eighty (64; 46, XX) probands with 21-hydroxylase deficiency were analyzed. 41 had SW, 34 had SV, and 5 had NC phenotype. Disease-causing mutations were identified in 158/160 alleles. The common mutations were Deletions/Large Gene Conversions (Del/LGC, 25.6%), p.293-13A/C>G (22.5%), and p.Ile173Asn(18.75%). Exon 6 cluster mutations (Ile236Asn, Val237Glu, Met238Lys) and p.Val282Leu were absent. c.-113G>A+p.Pro31Leu (6.87%) and p.Phe405Ser (2.5%) were rare recurrent mutations with a possible founder effect. Two novel variants (Exon 1, p.Leu49Arg, Exon 8, p.Leu362Ter) were identified and were estimated to have low enzyme activity (<2%). CONCLUSION: Del/LGC were the most common mutations identified. The c.-113G>A+p.Pro31Leu and p.Phe405Ser were recurrent variants with possible founder effect. This study also reiterates the low prevalence of NC CAH in Indian cohorts.