Project description:Genome-wide CRISPR screen in murine CH12F3-2 cell line to identify novel factors involved in antibody class switch recombination. FAM72A, a protein with no ascribed function, was identified in this screen as a major determinant during mutagenic uracil repair by antagonizing base excision repair protein UNG2.
Project description:Inhibition of fibroblast activation protein promotes cardiac repair by stabilizing brain natriuretic peptide after myocardial infarction
Project description:PIKKs are a family of kinases that control fundamental processes, including cell growth, DNA damage repair, and gene expression. Although their regulation and activities are well characterized, little is known about how PIKKs fold and assemble into active complexes. Previous work identified an Hsp90 cochaperone, the TTT complex, which specifically stabilizes PIKKs. Here we describe a mechanism by which TTT promotes their de novo maturation in fission yeast. We show that TTT recognizes newly synthesized PIKKs during translation. Although PIKKs form multimeric complexes, we found that they do not engage in cotranslational assembly with their partners. Rather, we accumulated evidence that TTT protects nascent PIKK polypeptides from misfolding and degradation and that PIKKs acquire their native state after translation is terminated. Thus, PIKK maturation and assembly are temporally segregated, suggesting that the biogenesis of large complexes requires both dedicated chaperones and cotranslational interactions between subunits.
Project description:The differentiation of naïve and memory B cells into antibody-secreting cells (ASCs) is a key feature of adaptive immunity. The requirement for phosphoinositide 3-kinase delta (PI3Kδ) to support B cell biology has been investigated intensively; however, specific functions of the related phosphoinositide 3-kinase-gamma (PI3Kγ) complex in B-lineage cells have not. Here we report that PI3Kγ promotes robust antibody responses induced by T cell-dependent antigens. The inborn error of immunity caused by human deficiency in PI3Kγ results in broad humoral defects, prompting our investigation of roles for this kinase in antibody responses using mouse models with bulk and single-cell transcriptome as well as B cell receptor repertoire sequencing.
Project description:The differentiation of naïve and memory B cells into antibody-secreting cells (ASCs) is a key feature of adaptive immunity. The requirement for phosphoinositide 3-kinase delta (PI3Kδ) to support B cell biology has been investigated intensively; however, specific functions of the related phosphoinositide 3-kinase-gamma (PI3Kγ) complex in B-lineage cells have not. Here we report that PI3Kγ promotes robust antibody responses induced by T cell-dependent antigens. The inborn error of immunity caused by human deficiency in PI3Kγ results in broad humoral defects, prompting our investigation of roles for this kinase in antibody responses using mouse models with bulk and single-cell transcriptome as well as B cell receptor repertoire sequencing.
Project description:PIKKs are a family of kinases that control fundamental processes, including cell growth, DNA damage repair, and gene expression. Although their regulation and activities are well characterized, little is known about how PIKKs fold and assemble into active complexes. Previous work identified an Hsp90 cochaperone, the TTT complex, which specifically stabilizes PIKKs. Here we describe a mechanism by which TTT promotes their de novo maturation in fission yeast. We show that TTT recognizes newly synthesized PIKKs during translation. Although PIKKs form multimeric complexes, we found that they do not engage in cotranslational assembly with their partners. Rather, we accumulated evidence that TTT protects nascent PIKK polypeptides from misfolding and degradation and that PIKKs acquire their native state after translation is terminated. Thus, PIKK maturation and assembly are temporally segregated, suggesting that the biogenesis of large complexes requires both dedicated chaperones and cotranslational interactions between subunits.