nupNUP

nupNUP is a fictional molecular entity introduced in speculative biology and science fiction to describe a hypothetical regulator of nucleocytoplasmic transport. The term blends the abbreviation NUP, used for nucleoporins that constitute the nuclear pore complex, with a doubled form to indicate a symmetric, dimeric structure.

In the fictional canon, nupNUP is a small protein, about 10-15 kDa, that forms a stable homodimer and binds selectively to FG-repeat nucleoporins. It is described as undergoing conformational changes in response to cellular signals, opening or closing a gate for cargo. Its activity is portrayed as essential for coordinating transport of large ribonucleoprotein complexes and certain signaling molecules.

Origins and usage: The concept appeared in speculative fiction and has since circulated in community wikis and game lore. Some authors treat nupNUP as an ancient element co-opted by advanced civilizations; others use it as a metaphor for redundancy in regulatory networks.

Etymology and naming: The name is a portmanteau of NUP, the standard symbol for nucleoporins, repeated to suggest symmetry and dimerization.

In real-world contexts, nupNUP is not recognized as a real protein or gene. It exists as a fictional construct used to explore ideas about protein interactions, cellular transport, and the role of symmetry in molecular regulation within imagined settings.