HNRNP PARTICLES

This article describes the discovery of nuclear DNA-like RNA (dRNA or hnRNA) and ribonucleoprotein particles in eukaryotes. Native hnRNA par ticles were isolated by sucrose gradient sedimentation and their struc tural organisation - nucleic acid (i.e. RNA) wrapped in a regular way on the surface of a series of globular protein particles - was determi ned. This led to the formulation of the informofer cycle hypothesis fo r the synthesis of hnRNA as a giant precursor molecule, its transport in informosomes within the nucleus, and subsequent splicing before exp ort from the nucleus as free mRNA.