Nup35-flox Mouse

Nup35, also known as Nup53 in vertebrates, is a nucleoporin that is part of the nuclear pore complex (NPC). NPCs are gateways for transport between the nucleus and cytoplasm in eukaryotic cells, and Nup35 is involved in multiple functions such as nuclear envelope assembly, nucleo-cytoplasmic transport, and regulation of gene expression [1]. It has been linked to various biological processes and disease conditions, making it an important gene for in vivo functional studies.

In a mouse model with a point mutation in the RNA recognition motif of the Nup35 gene, mice developed a severe megacolon due to a degenerative myopathy specifically affecting colonic smooth muscle, suggesting Nup35's role in maintaining smooth muscle function in the colon [3]. In Caenorhabditis elegans, depletion of Nup35/NPP-19 at restrictive temperature led to chromosome missegregation, nuclear morphology defects, and embryonic death around mid-gastrulation, indicating its crucial role in early embryonic nuclear assembly [1]. In cardiomyocytes, Nup35 regulates Na⁺-H⁺ exchanger-1 (NHE1) expression by controlling nhe1 mRNA nucleo-cytoplasmic trafficking, affecting cardiomyocyte pH homeostasis [2].

In conclusion, Nup35 plays essential roles in nuclear assembly during early embryogenesis, smooth muscle function in the colon, and cardiomyocyte pH homeostasis. The use of gene-modified mouse models and other in vivo systems has been instrumental in revealing these functions, providing insights into potential mechanisms underlying related diseases such as chronic intestinal pseudo-obstruction and ischemic cardiac diseases [1,2,3].