NMR backbone resonance assignments of the prodomain variants of BDNF in the urea denatured state

Brain derived neurotrophic factor (BDNF) is a member of the neurotrophin family of proteins which plays a central role in neuronal survival, growth, plasticity and memory. A single Val66Met variant has been identified in the prodomain of human BDNF that is associated with anxiety, depression and memory disorders. The structural differences within the full-length prodomain Val66 and Met66 isoforms could shed light on the mechanism of action of the Met66 and its impact on the development of neuropsychiatric-associated disorders. In the present study, we report the backbone 1H, 13C, and 15N NMR assignments of both full-length Val66 and Met66 prodomains in the presence of 2 M urea. These conditions were utilized to suppress residual structure and aid subsequent native state structural investigations aimed at mapping and identifying variant-dependent conformational differences under native-state conditions.Fil: Wang, Jing. Weill Cornell Medical College; Estados UnidosFil: Bains, Henrietta. Weill Cornell Medical College; Estados UnidosFil: Anastasia Gonzalez, Agustin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra. Universidad Nacional de Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra; ArgentinaFil: Bracken, Clay. Weill Cornell Medical College; Estados Unido

Trabecular thickening on mammography post-COVID vaccine and RSV vaccine: Case report

Ipsilateral axillary adenopathy post-COVID mRNA vaccine has been widely reported and guidelines for management have been established. Isolated changes of axillary tail trabecular thickening without associated adenopathy in the breast present a diagnostic dilemma and no official guidelines have thus far been reported. This finding has been reported after COVID mRNA vaccine and has never been reported with any other vaccine. We report on a patient with such changes on screening mammography 1.5 months after the fifth dose of a COVID-mRNA vaccine and 1 week after RSV vaccine. This raises the possibility that such changes can be seen with vaccines other than the COVID mRNA series of vaccines. The main differential diagnosis includes mastitis and inflammatory breast cancer. The transient nature of this finding with spontaneous resolution at diagnostic mammography and the vaccination history helps to establish the diagnosis and exclude breast cancer

Zinc induced structural changes in the intrinsically disordered BDNF Met prodomain confer synaptic elimination

Human brain derived neurotrophic factor (BDNF) encodes a protein product consisting of a C-terminal mature domain (mature BDNF) and an N-terminal prodomain, which is an intrinsically disordered protein. A common single nucleotide polymorphism in humans results in a methionine substitution for valine at position 66 of the prodomain, and is associated with memory deficits, depression and anxiety disorders. The BDNF Met66 prodomain, but not the Val66 prodomain, promotes rapid structural remodeling of hippocampal neurons’ growth cones and dendritic spines by interacting directly with the SorCS2 receptor. While it has been reported that the Met66 and Val66 prodomains exhibit only modest differences in structural propensities in the apo state, here we show that Val66 and Met66 prodomains differentially bind zinc (Zn). Zn2+ binds with higher affinity and more broadly impacts residues on the Met66 prodomain compared to the Val66 prodomain as shown by NMR and ITC. Zn2+ binding to the Met66 and Val66 prodomains results in distinct conformational and macroscopic differences observed by NMR, light scattering and cryoEM. To determine if Zn2+ mediated conformational change in the Met66 prodomain is required for biological effect, we mutated His40, a Zn2+ binding site, and observed a loss of Met66 prodomain bioactivity. As the His40 site is distant from the known region of the prodomain involved in receptor binding, we suggest that Met66 prodomain bioactivity involves His40 mediated stabilization of the multimeric structure. Our results point to the necessity of a Zn2+-mediated higher order molecular assembly of the Met66 prodomain to mediate neuronal remodeling.Fil: Wang, Jing. Weill Cornell Medicine; Estados UnidosFil: Anastasia Gonzalez, Agustin. Weill Cornell Medicine; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra. Universidad Nacional de Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra; ArgentinaFil: Bains, Henrietta. Weill Cornell Medicine; Estados UnidosFil: Giza, Joanna I.. Borough of Manhattan Community College; Estados UnidosFil: Clossey, David G.. Weill Cornell Medicine; Estados UnidosFil: Deng, Jingjing. New York University. School of Medicine; Estados UnidosFil: Neubert, Thomas A.. New York University Langone Health; Estados UnidosFil: Rice, William J.. New York University Langone Health; Estados UnidosFil: Lee, Francis S.. Weill Cornell Medicine; Estados UnidosFil: Hempstead, Barbara L.. Weill Cornell Medicine; Estados UnidosFil: Bracken, Clay. Weill Cornell Medicine; Estados Unido

mTORC2-NDRG1-CDC42 axis couples fasting to mitochondrial fission.

Fasting triggers diverse physiological adaptations including increases in circulating fatty acids and mitochondrial respiration to facilitate organismal survival. The mechanisms driving mitochondrial adaptations and respiratory sufficiency during fasting remain incompletely understood. Here we show that fasting or lipid availability stimulates mTORC2 activity. Activation of mTORC2 and phosphorylation of its downstream target NDRG1 at serine 336 sustains mitochondrial fission and respiratory sufficiency. Time-lapse imaging shows that NDRG1, but not the phosphorylation-deficient NDRG1Ser336Ala mutant, engages with mitochondria to facilitate fission in control cells, as well as in those lacking DRP1. Using proteomics, a small interfering RNA screen, and epistasis experiments, we show that mTORC2-phosphorylated NDRG1 cooperates with small GTPase CDC42 and effectors and regulators of CDC42 to orchestrate fission. Accordingly, RictorKO, NDRG1Ser336Ala mutants and Cdc42-deficient cells each display mitochondrial phenotypes reminiscent of fission failure. During nutrient surplus, mTOR complexes perform anabolic functions; however, paradoxical reactivation of mTORC2 during fasting unexpectedly drives mitochondrial fission and respiration