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Biology subjects

Friedman, A. E.

Publications and source records attributed to Friedman, A. E..

2 recordsLinked to original sources

Unique and overlapping behavioral effects of isoform-specific NRXN1 deletions across development

Mutations in the human neurexin 1 (NRXN1) gene are associated with neurodevelopmental disorders including autism and schizophrenia. Vertebrate NRXN1 produces three major NRXN1 isoforms, named , {beta}, and{gamma} . Human genetic data suggests that deletions located at the 5 region of the gene disrupting the isoform associate mostly with clinical behavioral deficits. Yet, 3 deletions that disrupt multiple isoforms have also been identified in clinical cases. Whether deletions that selectively affect specific NRXN1 isoforms result in specific behavioral deficits remains unclear. Here, we show that zebrafish harboring gene deletions that differentially encompass nrxn1a-, -{beta}, and/or -{gamma} display both unique and overlapping locomotion, sensorimotor behavior, and social behavior deficits. Combined, our results strongly support a model by which domain selective nrxn1 deletions predict behavioral phenotypes. Moreover, our results demonstrate compelling relationships between genotype and resulting behavioral phenotypes, providing functional insights into the complexity of NRXN1-associated neuropsychiatric behaviors.

neuroscience↗

Efficient Inhibition of O-glycan biosynthesis using the hexosamine analog Ac5GalNTGc

There is a critical need to develop small molecule inhibitors of mucin-type O-linked glycosylation. The best known reagent currently is peracetylated benzyl-GalNAc, but it is only effective at millimolar concentrations. This manuscript demonstrates that Ac5GalNTGc, a peracetylated C-2 sulfhydryl substituted GalNAc, fulfills this unmet need. When added to cultured leukocytes, breast and prostate cells, Ac5GalNTGc increased cell surface VVA-binding by ~10-fold, indicating truncation of O-glycan biosynthesis. Cytometry, mass spectrometry and Western blot analysis of HL-60 promyelocytes demonstrate that 50-80M Ac5GalNTGc prevented elaboration of 30-60% of the O-glycans beyond the Tn-antigen (GalNAc1-Ser/Thr) stage. The effect of the compound on N-glycans and glycosphingolipids was small. Glycan inhibition induced by Ac5GalNTGc resulted in 50-80% reduction in leukocyte sialyl-Lewis-X expression, and L-/P-selectin mediated rolling under flow. Ac5GalNTGc was pharmacologically active in mouse. It reduced neutrophil infiltration to sites of inflammation by ~60%. Overall, Ac5GalNTGc may find diverse applications as a potent inhibitor of O-glycosylation.

biochemistry↗