Polyamines, chromatin structure and transcription.
Nucleosomes are the basic elements of chromatin structure. Polyamines, such as spermine and spermidine, are small ubiquitous molecules absolutely required for cell growth. Photoaffinity polyamines bind to specific locations in nucleosomes and can change the helical twist of DNA in nucleosomes. Acetylation of polyamines reduces their affinity for DNA and nucleosomes, thus the helical twist of DNA in nucleosomes could be regulated by cells through acetylation. I suggest that histone and polyamine acetylation act synergistically to modulate chromatin structure. On naked DNA, the photoaffinity spermine bound preferentially to a specific 'TATA' sequence element, suggesting that polyamines may be involved in the unusual chromatin structure in this region. Further work is needed to test whether the specificities shown by photoaffinity polyamines are also shown by cellular polyamines; such experiments are now feasible.
Matthews
H R
HR
Department of Biological Chemistry, University of California, Davis 95616.
D000345:Affinity Labels; D001671:Biochemistry / Q000266:history; D002843:Chromatin / Q000378:metabolism / Q000648:ultrastructure*; D004247:DNA / Q000737:chemistry / Q000378:metabolism; D006657:Histones / Q000378:metabolism; D049673:History, 20th Century; D015394:Molecular Structure; D009690:Nucleic Acid Conformation; D009707:Nucleosomes / Q000648:ultrastructure; D011073:Polyamines / Q000737:chemistry / Q000378:metabolism*; D013096:Spermine / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism; D014158:Transcription, Genetic
D000345:Affinity Labels; D002843:Chromatin; D006657:Histones; D009707:Nucleosomes; D011073:Polyamines; D014157:Transcription Factors; D013096:Spermine; D004247:DNA