For the first time, the existence of mRNPs in human term placenta was investigated. These RNA-protein complexes were partly characterized. Our results showed that a great portion of the mRNA in human placenta is found in the post microsomal supernatant in the form of mRNP-particles. These mRNPs showed the following characteristics, found for mRNPs in other eucaryotic systems: The sedimentation constant of the complex was 16-18S as determined by analytical ultracentrifugation. Two peaks with buoyant densities of 1.393 and 1.415 g/cm3 were found for the particles on CsCl gradient centrifugation. RNA isolated from the fraction showed mRNA-activity while the particle by itself did not show this activity. Seven major polypeptides were found in the KCl-SDS treated mRNP-particles.
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|Published - 1982