The nuclear membrane protein Samp1 links peripheral genome organization to the myogenic transcriptional program
- 1Stockholm University
Abstract
Samp1 is an inner nuclear membrane protein required for myogenic differentiation and involved in chromatin organization at the nuclear periphery. Here, we investigated whether these functions are connected by studying the effects of Samp1 depletion during C2C12 myogenic differentiation using immunofluorescence microscopy, RNA sequencing, FRIC, and chromosome-positioning analysis. Samp1-depleted cells showed strongly reduced MyHC expression and virtually abrogated multinucleated fiber formation. Although cell-cycle withdrawal was not prevented, the transcriptional program driving differentiation was drastically perturbed, with reduced muscle-associated transcripts and incomplete repression of genes normally downregulated during myogenesis. Samp1 depletion also disrupted peripheral chromatin organization and prevented the accumulation of peripheral heterochromatin typically seen during differentiation. In addition, radial chromosome distribution was disrupted, evidenced by the failure of chromosome 8 to reposition to the nuclear periphery during differentiation. Together, these findings link the requirement for Samp1 in myogenic differentiation to its role in genome organization at the nuclear periphery.
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BibTeX
@misc{kasnik2026nuclear,
title = {{The nuclear membrane protein Samp1 links peripheral genome organization to the myogenic transcriptional program}},
author = {U. Kasnik and I. Mei and S. Gomez Alcalde and S. Aftab and E. Hedlund and E. Hallberg},
howpublished = {bioRxiv},
year = {2026},
month = sep,
doi = {10.64898/2026.09.24.754269},
url = {https://www.biorxiv.org/content/10.64898/2026.09.24.754269v1},
note = {CC BY},
}
RIS
TY - UNPB
TI - The nuclear membrane protein Samp1 links peripheral genome organization to the myogenic transcriptional program
AU - U. Kasnik
AU - I. Mei
AU - S. Gomez Alcalde
AU - S. Aftab
AU - E. Hedlund
AU - E. Hallberg
PY - 2026
DA - 2026/09/24
PB - bioRxiv
DO - 10.64898/2026.09.24.754269
UR - https://www.biorxiv.org/content/10.64898/2026.09.24.754269v1
AB - Samp1 is an inner nuclear membrane protein required for myogenic differentiation and involved in chromatin organization at the nuclear periphery. Here, we investigated whether these functions are connected by studying the effects of Samp1 depletion during C2C12 myogenic differentiation using immunofluorescence microscopy, RNA sequencing, FRIC, and chromosome-positioning analysis. Samp1-depleted cells showed strongly reduced MyHC expression and virtually abrogated multinucleated fiber formation. Although cell-cycle withdrawal was not prevented, the transcriptional program driving differentiation was drastically perturbed, with reduced muscle-associated transcripts and incomplete repression of genes normally downregulated during myogenesis. Samp1 depletion also disrupted peripheral chromatin organization and prevented the accumulation of peripheral heterochromatin typically seen during differentiation. In addition, radial chromosome distribution was disrupted, evidenced by the failure of chromosome 8 to reposition to the nuclear periphery during differentiation. Together, these findings link the requirement for Samp1 in myogenic differentiation to its role in genome organization at the nuclear periphery.
ER -