Researchers from University of Utah School of Medicine had reported that a key process in gene regulation could occur in human platelets. These are unique cells that are unusual because they don't have a nucleus (anucleate).
Scientists long have thought the transformation of pre-mRNA into mature mRNAŚcalled splicingŚhappens only in a cell's nucleus. But using stem cells from human umbilical cord blood to engineer the precursor cell that forms platelets and platelets isolated from the blood of study subjects, the Utah researchers found that splicing also takes place in the cytoplasm of circulating platelets.
AdvertisementThe U researchers, who report their findings in the August edition of the journal Cell, also identified the pre-mRNA in blood platelets that codes for Interleukin 1┬ (IL-1┬), a key protein in an ancient molecular system that plays major roles in inflammation, defense against infection, organ development, and disease. When blood platelets are activated through biochemical signals in response to injury, the IL-1┬ pre-mRNA is processed into the mature mRNA and then directs production of the critical inflammatory protein.
Finding that platelets can splice the IL-1┬ pre-mRNA was completely unexpected and emerged while the researchers were engaged in earlier studies of how platelets communicate with certain leukocytes (white blood cells). During that investigation the scientists had found evidence of platelets making new proteins, which led them to pursue the mechanisms that are involved.
Researchers theorize that splicing outside the nucleus is one of a number of intricate ways the body maintains more precise control over gene expression. Many of these control mechanisms are just coming to light.