title: A unique subspecies of histone H4 mRNA from rat myoblasts contains poly(A).
abstract: Fractionation of rat L6 myoblast histone H4 mRNA into its three component subspecies revealed that one of the major subspecies (H4-1) contained poly(A). The unique poly(A)+ H4 mRNA makes up about 8% of the total polysomal H4 mRNA population detected. Unlike the poly(A)- histone mRNAs, whose levels are reduced by greater than 95% when myoblasts differentiate into myotubes, the poly(A)+ subspecies is reduced by only 70%. The poly(A)+ H4 mRNA from myotubes incubated with actinomycin D decays with a half-life of 37-42 min, which is similar to that obtained for the poly(A)- H4 mRNAs in myoblasts. Both the poly(A)+ and poly(A)- subspecies decay at an increased rate after inhibition of DNA synthesis. In myoblasts the poly(A)+ H4 mRNA exists almost exclusively in the polysomal compartment (greater than 95%) with little (less than 5%) in the free ribonucleoprotein (mRNA-protein or mRNP) complex compartment of the cell. Poly(A)- histone H4 mRNA subspecies, on the other hand, are distributed with approximately 80% in the polysomal compartment and 20% in the free mRNP complex compartment. The unique poly(A)+ H4 mRNA is unusual, not only in that it contains poly(A) but also in its behavior compared to poly(A)- H4 mRNAs during terminal differentiation.
authors.forename: R C
authors.initials: RC
authors.lastname: Bird
authors.forename: F A
authors.initials: FA
authors.lastname: Jacobs
authors.forename: G
authors.initials: G
authors.lastname: Stein
authors.forename: J
authors.initials: J
authors.lastname: Stein
authors.forename: B H
authors.initials: BH
authors.lastname: Sells
mesh_terms: D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D006657:Histones / Q000235:genetics*; D007700:Kinetics; D008970:Molecular Weight; D009132:Muscles / Q000378:metabolism*; D011061:Poly A / Q000235:genetics / Q000302:isolation & purification*; D012333:RNA, Messenger / Q000235:genetics / Q000302:isolation & purification*; D051381:Rats
chemical_list: D006657:Histones; D012333:RNA, Messenger; D011061:Poly A