Investigation of the interaction of FAT10 and VCP (p97)

In the present study the interaction of the ubiquitin-like modifier HLA-F adjacent transcript 10 (FAT10) with the putative substrate Valosin-containing protein (VCP) was investigated. VCP is a hexameric ATPase associated with various activities (AAA) and extracts proteins from the Endoplasmic Reticulum (ER) membrane or from protein complexes. In this function as a segregase VCP is involved in different ubiquitin-dependent processes reaching from the ER associated degradation (ERAD) and cell cycle regulation to membrane fusion events.In addition to a minor covalent attachment of FAT10 to VCP, which led to the degradation of the VCP-FAT10 conjugate by the proteasome, the more prominent non-covalent interaction of both proteins was examined in more detail and the functional consequences arising out of it. It was shown that FAT10 and VCP interact under endogenous conditions and further in vitro experiments revealed that they interact directly. Treatment with the VCP specific inhibitor Eeyarestatin I or use of an ATPase dead VCP mutant didn’t alter the degradation rate of bulk FAT10 conjugates, whereas treatment with the inhibitor DBeQ increased the degradation rate of the FAT10 conjugates. Furthermore the effect of FAT10 on VCP function was studied. Neither the hexamer stability nor the ATPase activity of VCP was influenced by FAT10. Only a difference in the degradation of the ERAD model substrate a1-Antitrypsin was observed in preliminary experiments. Taken all results together it can be concluded that the consequences of the VCP-FAT10 interaction are different to consequences arising from the interaction of VCP with ubiquitin, and that the FAT10-VCP interaction might play a specific role in the immune system or during inflammatory processes when FAT10 is highly up-regulated

Lactation support in neonatal intensive care units in Germany from the mothers’ perspective – a mixed-method study of the current status and needs

Schwab I, Wullenkord R, Eyssel F, Dresbach T, Scholten N. Lactation support in neonatal intensive care units in Germany from the mothers’ perspective – a mixed-method study of the current status and needs. BMC Pregnancy and Childbirth. 2024;24(1): 282.**Abstract** **Background** Establishing successful lactation in mothers of very low birth weight (VLBW, <1500g) infants requires structured lactation support. Little is known about mothers’ perspectives on lactation support in German neonatal intensive care units (NICUs). **Methods** This paper features a convergent mixed-method approach that includes a retrospective, cross-sectional questionnaire and interview data to showcase mothers’ perceptions of lactation support in NICUs. Content analysis of the interviews (n = 12) and a descriptive analysis of quantitative data (n = 533) were performed to illustrate the current status and need for lactation support in German NICUs. **Results** The results show that lactation support in German NICUs is often inadequate and does not comply with recommendations based on the existing literature to encourage pumping and breastfeeding in mothers. The data imply that even if lactation is successfully initiated in most cases, it is often not maintained over time, which may be due to a lack of personal support and consistent information. **Conclusion** The overall structures and institutional guidelines for lactation support should be encouraged to promote nutrition with mother´s own milk in German NICUs. </p

Achieving sufficient milk supply supports mothers to cope with premature birth

Schwab I, Wullenkord R, Ohnhäuser T, Dresbach T, Scholten N. Achieving sufficient milk supply supports mothers to cope with premature birth. Acta Paediatrica. 2024.**Abstract** **Aim** To explore whether and how expressing breast milk is perceived as helpful in coping with negative emotions due to premature birth by mothers of very low birth weight (VLBW) infants. **Methods** Qualitative interviews and a retrospective cross‐sectional questionnaire with mothers of VLBW infants were conducted and analysed using an exploratory sequential mixed‐method design. Hypotheses were built using qualitative content analysis and quantitatively tested using multivariate regression analysis. **Results** Interviews with 12 mothers and questionnaires of 518 mothers were analysed. Coping with prematurity by expressing milk was seen as a way to maintain the caregiving role for the mothers, where three relevant factors arouse: making up for what happened, providing the best for their infant and fear of low milk supply. Quantitative analysis showed that mothers with a high milk supply (Coef. = 1.1,p p = 0.015) perceived expressing breast milk significantly more as a resource for coping. **Conclusion** This study adds knowledge on how expressing breast milk for their VLBW infant may support mothers in coping with premature birth, by revealing the association with milk supply and feelings of guilt due to premature birth. </p

Lactation support in neonatal intensive care units in Germany from the mothers’ perspective – a mixed-method study of the current status and needs

Abstract Background Establishing successful lactation in mothers of very low birth weight (VLBW, <1500g) infants requires structured lactation support. Little is known about mothers’ perspectives on lactation support in German neonatal intensive care units (NICUs). Methods This paper features a convergent mixed-method approach that includes a retrospective, cross-sectional questionnaire and interview data to showcase mothers’ perceptions of lactation support in NICUs. Content analysis of the interviews (n = 12) and a descriptive analysis of quantitative data (n = 533) were performed to illustrate the current status and need for lactation support in German NICUs. Results The results show that lactation support in German NICUs is often inadequate and does not comply with recommendations based on the existing literature to encourage pumping and breastfeeding in mothers. The data imply that even if lactation is successfully initiated in most cases, it is often not maintained over time, which may be due to a lack of personal support and consistent information. Conclusion The overall structures and institutional guidelines for lactation support should be encouraged to promote nutrition with mother´s own milk in German NICUs

Immuno- and constitutive proteasome crystal structures reveal differences in substrate and inhibitor specificity

Constitutive proteasomes and immunoproteasomes shape the peptide repertoire presented by major histocompatibility complex class I (MHC-I) molecules by harboring different sets of catalytically active subunits. Here, we present the crystal structures of constitutive proteasomes and immunoproteasomes from mouse in the presence and absence of the epoxyketone inhibitor PR-957 (ONX 0914) at 2.9 Å resolution. Based on our X-ray data, we propose a unique catalytic feature for the immunoproteasome subunit Beta5i/LMP7. Comparison of ligand-free and ligand-bound proteasomes reveals conformational changes in the S1 pocket of Beta5c/X but not Beta5i, thereby explaining the selectivity of PR-957 for Beta5i. Time-resolved structures of yeast proteasome: PR-957 complexes indicate that ligand docking to the active site occurs only via the reactive head group and the P1 side chain. Together, our results support structure-guided design of inhibitory lead structures selective for immunoproteasomes that are linked to cytokine production and diseases like cancer and autoimmune disorders

The structure of the ubiquitin-like modifier FAT10 reveals an alternative targeting mechanism for proteasomal degradation

FAT10 is a ubiquitin-like modifier that directly targets proteins for proteasomal degradation. Here, we report the high-resolution structures of the two individual ubiquitin-like domains (UBD) of FAT10 that are joined by a flexible linker. While the UBDs of FAT10 show the typical ubiquitin-fold, their surfaces are entirely different from each other and from ubiquitin explaining their unique binding specificities. Deletion of the linker abrogates FAT10-conjugation while its mutation blocks auto-FAT10ylation of the FAT10-conjugating enzyme USE1 but not bulk conjugate formation. FAT10- but not ubiquitin-mediated degradation is independent of the segregase VCP/p97 in the presence but not the absence of FAT10's unstructured N-terminal heptapeptide. Stabilization of the FAT10 UBDs strongly decelerates degradation suggesting that the intrinsic instability of FAT10 together with its disordered N-terminus enables the rapid, joint degradation of FAT10 and its substrates without the need for FAT10 de-conjugation and partial substrate unfolding.publishe

Structured lactation support and human donor milk for German NICUs-Protocol on an intervention design based on a multidimensional status quo and needs assessment (Neo-MILK).

IntroductionMother's own milk is the best nutrition for every newborn and especially for vulnerable infants such as preterm infants with a very low birth weight below 1,500 grams (VLBW). If no MOM is available, human donor milk is the alternative of choice. Mothers of preterm born infants face challenging conditions that impair sufficient milk production. For this reason, it is particularly important to provide structural lactation support and, at the same time, to promote the establishment of human donor milk banks.Methods and analysisVia a multidisciplinary approach the Neo-MILK study will develop an intervention for structured breastfeeding and lactation support. This will be based on a comprehensive status quo and needs assessment. In addition, the implementation of human donor milk banks (HDMB) will be supported by the development of standards.Ethics and disseminationIntervention development is participatory, involving different disciplines and stakeholders. All surveys are subject to approval by the ethics committee. During the course of the project, the results will be communicated to the scientific community and the general public via publications, the project homepage and social media.Trial registration numberDRKS00024799 (German Clinical Trials Register)

Author Correction: The structure of the ubiquitin-like modifier FAT10 reveals an alternative targeting mechanism for proteasomal degradation

The original version of the Supplementary Information associated with this Article inadvertently omitted Supplementary Table 3. The HTML version of the Article has been updated to include a corrected version of the Supplementary Information

Alignment and Relaxation Dynamics of Dye Molecules in Host-Guest Inclusion Compounds As Probed by Dielectric Spectroscopy

The alignment and relaxation dynamics of a polar dye molecule, N,N-dimethyl-4(4-nitrophenylazo)aniline (DNAA), in zeolite L and perhydrotriphenylene (PHTP) channels were investigated by means of a combination of optical, dielectric, and quantum-chemical methods. Both the zeolite L and PHTP channels enable the dye molecules to align along the channel axis. An amplified net dipole moment of DNAA in PHTP is observed and attributed to enhanced 1D close alignment of dye molecules. In zeolite L channels, a concentration gradient is found with aggregation at the channel entrances. The dynamics of the dye in zeolite L channels reveals localized conical rotational fluctuation modes following Arrhenius-type activation with energy of 0.31 eV, which we assign to small noninteracting fluctuating polar units of the dyes being loosely aligned or isolated. Unlike zeolite L, relaxations in PHTP are characterized by cooperative wobbling motions interpreted as increased intermolecular dipole interaction due to a closely packed one-dimensional array. Temperature-dependent activation energies of 0.25 eV below 0 degrees C and 0.37 eV at ambient temperature reflect the role of the soft channel walls in the activation process.status: publishe