Search for: All records

Abstract Protein activity, abundance, and stability can be regulated by post-translational modification including ubiquitination. Ubiquitination is conserved among eukaryotes and plays a central role in modulating cellular function; yet, we lack comprehensive catalogs of proteins that are modified by ubiquitin in plants. In this study, we describe an antibody-based approach to enrich ubiquitinated peptides coupled with isobaric labeling to enable quantification of up to 18-multiplexed samples. This approach identified 17,940 ubiquitinated lysine sites arising from 6,453 proteins from Arabidopsis (Arabidopsis thaliana) primary roots, seedlings, and rosette leaves. Gene ontology analysis indicated that ubiquitinated proteins are associated with numerous biological processes including hormone signaling, plant defense, protein homeostasis, and metabolism. We determined ubiquitinated lysine residues that directly regulate the stability of three transcription factors, CRYPTOCHROME-INTERACTING BASIC-HELIX-LOOP-HELIX 1 (CIB1), CIB1 LIKE PROTEIN 2 (CIL2), and SENSITIVE TO PROTON RHIZOTOXICITY1 (STOP1) using in vivo degradation assays. Furthermore, codon mutation of CIB1 to create a K166R conversion to prevent ubiquitination, via CRISPR/Cas9-derived adenosine base editing, led to an early flowering phenotype and increased expression of FLOWERING LOCUS T (FT). These comprehensive site-level ubiquitinome profiles provide a wealth of data for future functional studies related to modulation of biological processes mediated by this post-translational modification in plants. 

Gender is one of the central categories organizing children’s social world. Clear patterns of gender development have been well-documented among cisgender children (i.e., children who identify as a gender that is typically associated with their sex assigned at birth). We present a comprehensive study of gender development (e.g., gender identity and gender expression) in a cohort of 3- to 12-y-old transgender children (n = 317) who, in early childhood, are identifying and living as a gender different from their assigned sex. Four primary findings emerged. First, transgender children strongly identify as members of their current gender group and show gender-typed preferences and behaviors that are strongly associated with their current gender, not the gender typically associated with their sex assigned at birth. Second, transgender children’s gender identity (i.e., the gender they feel they are) and gender-typed preferences generally did not differ from 2 comparison groups: cisgender siblings (n = 189) and cisgender controls (n = 316). Third, transgender and cisgender children’s patterns of gender development showed coherence across measures. Finally, we observed minimal or no differences in gender identity or preferences as a function of how long transgender children had lived as their current gender. Our findings suggest that early sex assignment and parental rearing based on that sex assignment do not always define how a child identifies or expresses gender later.