Biology subjects

Tarkowski, B.

Publications and source records attributed to Tarkowski, B..

4 recordsLinked to original sources

bioRxiv2023

Polyadenylation of mRNAs encoding secreted proteins by TENT5 family of enzymes is essential for gametogenesis in mice.

Cytoplasmic polyadenylation plays a vital role in gametogenesis, however, the participating enzymes and substrates in mammals remain unclear. Using knockout and knock-in mouse models, we describe the essential role of 4 TENT5 poly(A) polymerases in mice fertility and gametogenesis. TENT5B and TENT5C play crucial, but redundant roles in oogenesis, with double knockout of both genes leading to oocyte degeneration. Additionally, TENT5B-GFP knock-in females display gain-of-function infertility effect with multiple chromosomal aberrations in ovulated oocytes. TENT5C and TENT5D both regulate different stages of spermatogenesis, shown by sterility of males with either genes knockout mutation. Finally, Tent5a knockout significantly lowers fertility, although the underlying mechanism is not directly related to gametogenesis. Through Direct RNA sequencing we discovered that TENT5s polyadenylate mRNAs encoding endoplasmic reticulum-targeted proteins essential for gametogenesis. Sequence motives analysis and reporter mRNA assay revealed that the presence of endoplasmic reticulum-leader represents the primary determinant of TENT5-mediated regulation.

developmental biology↗

bioRxiv2022

SARS-CoV-2 mRNA vaccine is re-adenylated in vivo, enhancing antigen production and immune response

Though mRNA vaccines against COVID-19 have revolutionized vaccinology and have been administered in billions of doses, we know incredibly little about how mRNA vaccines are metabolized in vivo. Here we implemented enhanced nanopore Direct RNA sequencing (eDRS), to enable the analysis of single Modernas mRNA-1273 molecules, giving in vivo information about the sequence and poly(A) tails. We show that mRNA-1273, with all uridines replaced by N1-methylpseudouridine (m{Psi}), is terminated by a long poly(A) tail (~100 nucleotides) followed by an m{Psi}Cm{Psi}AG sequence. In model cell lines, mRNA-1273 is swiftly degraded in a process initiated by the removal of m{Psi}Cm{Psi}AG, followed by CCR4-NOT-mediated deadenylation. In contrast, intramuscularly inoculated mRNA-1273 undergoes more complex modifications. Notably, mRNA-1273 molecules are re-adenylated after m{Psi}Cm{Psi}AG removal. Detailed analysis of immune cells involved in antigen production revealed that in macrophages, after m{Psi}Cm{Psi}AG removal, vaccine mRNA is very efficiently re-adenylated, and poly(A) tails can reach up to 200A. In contrast, in dendritic cells, vaccine mRNA undergoes slow deadenylation-dependent decay. We further demonstrate that enhancement of mRNA stability in macrophages is mediated by TENT5 poly(A) polymerases, whose expression is induced by the vaccine itself. Lack of TENT5-mediated re-adenylation results in lower antigen production and severely compromises specific immunoglobulin production following vaccination. Together, our findings provide an unexpected principle for the high efficacy of mRNA vaccines and open new possibilities for their improvement. They also emphasize that, in addition to targeting a protein of interest, the design of mRNA therapeutics should be customized to its cellular destination.

immunology↗

bioRxiv2020

Cytoplasmic polyadenylation by TENT5A is required for proper bone formation

Osteoblasts orchestrate bone formation by secreting dense, highly cross-linked type I collagen and other proteins involved in osteogenesis. Mutations in Col11, Col12, or collagen biogenesis factors lead to the human genetic disease, osteogenesis imperfecta (OI). Herein, we show that the TENT5A gene, whose mutation is responsible for poorly characterized type XVIII OI, encodes an active cytoplasmic poly(A) polymerase regulating osteogenesis. TENT5A is induced during osteoblast differentiation and TENT5A KO osteoblasts are defective in mineralization. The TENT5A KO mouse recapitulates OI disease symptoms such as bone fragility and hypomineralization. Direct RNA sequencing revealed that TENT5A polyadenylates and increases expression of Col11 and Col12 RNAs, as well as those of other genes mutated in OI, resulting in lower production and improper folding of collagen chains. Thus, we have identified the specific pathomechanism of XVIII OI and report for the first time a biologically relevant post-transcriptional regulator of collagen production. We further postulate that TENT5A, possibly together with its paralogue TENT5C, is responsible for the wave of cytoplasmic polyadenylation of mRNAs encoding secreted proteins occurring during bone mineralization.

genetics↗

bioRxiv2019

B-cell humoral response and differentiation is regulated by non-canonical poly(A) polymerase TENT5C

TENT5C is a non-canonical cytoplasmic poly(A) polymerase (ncPAP) upregulated in activated B cells and suppressing their proliferation. Herein we measured the global distribution of poly(A) tail lengths in responsive B cells using a modified Nanopore direct RNA-sequencing approach and revealed that TENT5C polyadenylates immunoglobulin mRNAs regulating their steady-state levels. Consequently, TENT5C deficient B cells secrete less antibodies and KO mice have diminished gamma globulin concentrations despite the increased number of CD138high plasma cells as a consequence of accelerated differentiation. TENT5C is explicitly upregulated in differentiating plasma cells by innate signaling. Importantly, TENT5C deficiency in B lymphocytes impairs the capacity of the secretory pathway through the reduction of ER volume and downregulation of unfolded protein response.\n\nOur findings define the role of the TENT5C enzyme in B cell physiology and discover the first ncPAP engaged in the regulation of immunoglobulin mRNA poly(A) tails, thus serving as a regulator of humoral immunity.

immunology↗