The topoisomerase 1-interacting protein BTBD1 is essential for muscle cell differentiation

Abstract

DNA topoisomerase I (Topo1) contributes to vital biological functions, but its regulation is not clearly understood. The BTBD1 protein was recently cloned on the basis of its interaction with the core domain of Topo1 and is expressed particularly in skeletal muscle. To determine BTBD1 functions in this tissue, the in vitro model used was the C2C12 mouse muscle cell line, which expresses BTBD1 mainly after myotube differentiation. We studied the effects of a stably overexpressed BTBD1 protein truncated of the 108 N-terminal amino-acid residues and harbouring a C-terminal FLAG tag (D-BTBD1). The proliferation speed of D-BTBD1 C2C12 cells was significantly decreased and no myogenic differentiation was observed, although these cells maintained their capacity to enter adipocyte differentiation. These alterations could be related to Topo1 deregulation. This hypothesis is further supported by the decrease in nuclear Topo1 content in D-BTBTD1 proliferative C2C12 cells and the switch from the main peripheral nuclear localization of Topo1 to a mainly nuclear diffuse localization in D-BTBTD1 C2C12 cells. Finally, this study demonstrated that BTBD1 is essential for myogenic differentiation.

PED/PEA-15 induces autophagy and mediates TGF-beta1 effect on muscle cell differentiation

“…7, 8, 9, 21 As previously reported, 7, 8, 9 the L6 and C2C12 myotube formation is accompanied by upregulation of a number of genes including MyoD1 , myogenin and GLUT4 . Unexpectedly, however, these same gene profile studies revealed that expression of the autophagy regulator PED/PEA-15 underwent progressive reduction both during L6 and C2C12 cell differentiation (Figure 1a, left panel).…”

“…These include BECLIN1, ATG8, Gabarapl1, ATG12, ATG4B and VSP34. 21, 22, 23, 24 FoxO1, in turn, is highly regulated at the post-transcriptional level. Dephosphorylation at Ser256 by the Ser/Thr phosphatase PP2A activates FoxO1, inducing its nuclear translocation.…”

Identification of dosage‐sensitive genes in fetuses referred with severe isolated congenital diaphragmatic hernia

“…BNC1 is involved in cell proliferation, and defective cell proliferation and migration in the PPFs of the developing diaphragm have been proposed to underlie CDH . Given the musculature of the diaphragm, BTBD1 is an interesting candidate involved in myoblast growth and differentiation …”

Short Hairpin RNA Gene Silencing of Prolyl Hydroxylase-2 with a Minicircle Vector Improves Neovascularization of Hindlimb Ischemia

“…At 70%-80% confluence, cells were transfected with 4 lg of plasmids carrying the Luc reporter gene (PL-Luc) or equimolar 2 lg of MC carrying the Luc reporter gene (MC-Luc), using Lipofectamine 2000 (Invitrogen) according to the manufacturer's protocol. C2C12 cells show rapid proliferation with a doubling time of approximately 19 hr in vitro (Pisani et al, 2004). In order to more closely resemble the in vivo conditions of slower proliferating cells, C2C12 cells were exposed to 9,000 rad 3 hr before transfection, resulting in an optimal proliferation pattern (Supplementary Fig.…”