KIF1Bβ transports dendritically localized mRNPs in neurons and is recruited to synapses in an activity-dependent manner

KIF1Bβ is a kinesin-like, microtubule-based molecular motor protein involved in anterograde axonal vesicular transport in vertebrate and invertebrate neurons. Certain KIF1Bβ isoforms have been implicated in different forms of human neurodegenerative disease, with characterization of their functional integration and regulation in the context of synaptic signaling still ongoing. Here, we characterize human KIF1Bβ (isoform NM015074), whose expression we show to be developmentally regulated and elevated in cortical areas of the CNS (including the motor cortex), in the hippocampus, and in spinal motor neurons. KIF1Bβ localizes to the cell body, axon, and dendrites, overlapping with synaptic-vesicle and postsynaptic-density structures. Correspondingly, in purified cortical synaptoneurosomes, KIF1Bβ is enriched in both pre- and postsynaptic structures, forming detergent-resistant complexes. Interestingly, KIF1Bβ forms RNA–protein complexes, containing the dendritically localized Arc and Calmodulin mRNAs, proteins previously shown to be part of RNA transport granules such as Purα, FMRP and FXR2P, and motor protein KIF3A, as well as Calmodulin. The interaction between KIF1Bβ and Calmodulin is Ca⁺²-dependent and takes place through a domain mapped at the carboxy-terminal tail of the motor. Live imaging of cortical neurons reveals active movement by KIF1Bβ at dendritic processes, suggesting that it mediates the transport of dendritically localized mRNAs. Finally, we show that synaptic recruitment of KIF1Bβ is activity-dependent and increased by stimulation of metabotropic or ionotropic glutamate receptors. The activity-dependent synaptic recruitment of KIF1Bβ, its interaction with Ca²⁺ sensor Calmodulin, and its new role as a dendritic motor of ribonucleoprotein complexes provide a novel basis for understanding the concerted co-ordination of motor protein mobilization and synaptic signaling pathways.     

Monstrilloids (Crustacea: Copepoda) from the Mediterranean Sea (Northern Adriatic Sea), with a description of six new species

Monstrilloid copepods collected during zooplankton surveys carried out over several years (2009–2016) in the Gulf of Trieste, northern Adriatic Sea, were examined. A total of seven species were found, of which six are undescribed, five of Cymbasoma and one of Monstrilla. These new species are described, illustrated and compared herein with its known congeners. Two of them are related to the C. rigidum species complex. One of these species is described based on both the male and the female; sexes were linked by identical details of the cephalic structure and the antennulary armature. Two previous reports of females attributed to C. tumorifrons from the Mediterranean relate to specimens that in fact belong to a new species, C. mediterranea. The most abundant species was M. grandis, which had a remarkable aggregation around the Trieste harbour in 2015. Male and female specimens of this assumedly widespread species were examined and the observed intra-specific morphological variability is reported and compared with previous illustrated reports; this nominal species probably this nominal species, probably represents a species complex. The addition of the new species here described brings the number of nominal species in the Mediterranean-Black Sea region to 26.

www.zoobank.org/urn:lsid:zoobank.org:pub:3D4B38E4-CCCD-4BD6-AC57-B59343A865F7     

A large Bayesian VAR with a block-specific shrinkage: A forecasting application for Italian industrial production

This paper proposes a Bayesian vector autoregression (BVAR) model with the Kalman filter to forecast the Italian industrial production index in a pseudo real-time experiment. Minnesota priors are adopted as a general framework, but a different shrinkage pattern is imposed for both the VAR coefficients and the Kalman gain, depending on the informative contribution of each variable investigated at frequency level. Both a time-varying and a constant selection for the shrinkage are proposed. Overall, the new BVAR models significantly improve the forecasting performance in comparison with the more traditional versions based on standard Minnesota priors with a single shrinkage, equal for all the variables, and selected on the basis of some optimal criteria. Very promising results come out in terms of density forecasting as well.     

Functional interactions between the gut microbiota and host metabolism

The link between the microbes in the human gut and the development of obesity, cardiovascular disease and metabolic syndromes, such as type 2 diabetes, is becoming clearer. However, because of the complexity of the microbial community, the functional connections are less well understood. Studies in both mice and humans are helping to show what effect the gut microbiota has on host metabolism by improving energy yield from food and modulating dietary or the host-derived compounds that alter host metabolic pathways. Through increased knowledge of the mechanisms involved in the interactions between the microbiota and its host, we will be in a better position to develop treatments for metabolic disease.     

Dose-related effects of sericin on preadipocyte behavior within collagen/sericin hybrid scaffolds

This paper aims at demonstrating the biocompatibility of recently developed 3D hydrogel scaffolds containing the same amount of collagen(COLL) and variable concentrations of sericin(SS) in order to find the most suitable formula for adipose tissue engineering(ATE) applications.These scaffolds were obtained by COLL crosslinking with glutaraldehyde followed by freeze-drying and, subsequently, seeded with 3T3-L1 preadipocytes. Scanning electron microscopy studies revealed the scaffolds' architecture and cellular colonization. Also, in vitro biocompatibility of the developed scaffolds was evaluated by LDH and MTT assays and Live/Dead analysis of 3T3-L1 preadipocyte populating these 3D matrices.The best results in terms of cell survival and proliferation status were obtained in the case of the hybrid COLL scaffold containing 40% SS(COLL–SS4). Furthermore, the biological performance of the analyzed COLL-based hydrogels at 5- and 8- days post-seeding was found to decrease as follows: COLL–SS4 4 COLL–SS2 4 COLL 4 COLL–SS6. Consequently, our study highlights that hybrid scaffolds obtained by the addition of variable concentrations of SS to a constant COLL composition positively influences the behavior of 3T3-L1 cells with the exception of the COLL–SS6 matrix(60% SS). Altogether, the data obtained recommend SS as a component of COLL-based hydrogels providing them with features that may be useful in ATE applications.     

Gerodermia osteodysplastica is caused by mutations in SCYL1BP1, a Rab-6 interacting golgin

Gerodermia osteodysplastica is an autosomal recessive disorder characterized by wrinkly skin and osteoporosis. Here we demonstrate that gerodermia osteodysplastica is caused by loss-of-function mutations in SCYL1BP1, which is highly expressed in skin and osteoblasts. The protein localizes to the Golgi apparatus and interacts with Rab6, identifying SCYL1BP1 as a golgin. These results associate abnormalities of the secretory pathway with age-related changes in connective tissues.