Year: 2026
Type: preprint
Abstract: In Caenorhabditis elegans embryos, the nuclear transport receptor IMB-2 (Importin Beta Family-2, a karyopherin β 2) preferentially localizes to the nuclear envelope along with its encoding mRNA. This suggests that imb-2 mRNA is locally translated at the nuclear envelope. To test whether imb-2 ’s two putative human orthologs, Transportin 1 (TNPO1) and Transportin 2 (TNPO2), exhibited similar mRNA localization, we performed smiFISH and microscopy in U2OS, HeLa, and human pluripotent stem cells. Neither human TNPO1 nor TNPO2 mRNA localized to the nuclear envelope in any tested human cell type. However, the human TNPO1 protein and the C. elegans IMB-2 protein both localized to the nucleus and its periphery. This suggests that despite their shared functional roles these karyopherins have different routes to expression. Article summary Gene expression is a multistep process. Genes are transcribed into mRNA in nuclei and translated into proteins in the cytoplasm. C. elegans imb-2 localizes preferentially at the nuclear envelope for reasons that are unclear. We asked whether human imb-2 homologs also localize at the nuclear envelope. Two imb-2 orthologs in humans, Transportin-1 and 2, showed no preference for the nuclear envelope. However, once translated, they all shared the same nuclear localization and all function to move proteins in and out. This work will appeal to geneticists, cell biologists, and molecular biologists.
Institution: Colorado State University
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: green
Awards: G2586609609, G2796167598, MRI Collaborative Consortium: Acquisition of a Shared Supercomputer by the Rocky Mountain Advanced Computing Consortium, G4958434179, MRI Collaborative Consortium: Acquisition of a Shared Supercomputer by the Rocky Mountain Advanced Computing Consortium, CAREER: The Spatiotemporal Dynamics of the C. Elegans Intestinal Gene Regulatory Network, G8929392486, Caenorhabditis Genetics Center, mRNA regulation, localization, and dynamics in C. elegans embryogenesis
OpenAlex ID: W7161970127