PT  - JOURNAL ARTICLE
AU  - Aleksandra Bilska
AU  - Monika Kusio-Kobiałka
AU  - Paweł S. Krawczyk
AU  - Olga Gewartowska
AU  - Bartosz Tarkowski
AU  - Kamil Kobyłecki
AU  - Jakub Gruchota
AU  - Ewa Borsuk
AU  - Andrzej Dziembowski
AU  - Seweryn Mroczek
TI  - B cell humoral response and differentiation is regulated by the non-canonical poly(A) polymerase TENT5C
AID  - 10.1101/686683
DP  - 2019 Jan 01
TA  - bioRxiv
PG  - 686683
4099  - http://biorxiv.org/content/early/2019/07/09/686683.short
4100  - http://biorxiv.org/content/early/2019/07/09/686683.full
AB  - 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.Our 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.