Biomaterial Database

Nonrandom distribution of histone mRNAs into polysomes and nonpolysomal ribonucleoprotein particles in sea urchin embryos. 1982

E J Baker, and A A Infante

In the early sea urchin embryo, newly synthesized cytoplasmic histone mRNA is found both on polysomes and free of ribosomes as nonpolysomal messenger ribonucleoprotein particles (free RNPs). The distribution of newly synthesized histone mRNAs between translating and nontranslating compartments is nonrandom and dependent on the developmental stage. Gel electrophoresis and autoradiography of polysomal and free RNP RNA from embryos at various stages show that (i) the fraction of total newly synthesized histone mRNA that is in polysomes is greater than the fraction of total newly synthesized poly(A)+mRNA that is in polysomes, at all stages examined, and (ii) among the five histone mRNAs. H1 mRNA and H4 mRNA are relatively more enriched in the free RNPs than are the mRNAs for H2A, H2B, and H3. These data suggest that histone mRNA, as a class, is more efficiently utilized as a template than the average mRNA and, of the cytoplasmic histone mRNAs, the mRNAs for histones H2A, H2B, and possibly H3 are selected more frequently for translation than those for H1 and H4. Cell-free translations of polysomal and free RNP RNAs yield different ratios of in vitro histone products, consistent with the RNA distribution data. To test the possibility that the in vivo distribution of the histone mRNAs is the consequence of different intrinsic initiation capabilities of the individual mRNAs, ribosome-binding assays were carried out and unequal binding abilities of the histone mRNAs in the reticulocyte lysate were shown. A translational level component in the regulation of histone synthesis in the sea urchin embryo is indicated.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D009698	Nucleoproteins	Proteins conjugated with nucleic acids.	Nucleoprotein
D010944	Plants	Multicellular, eukaryotic life forms of kingdom Plantae. Plants acquired chloroplasts by direct endosymbiosis of CYANOBACTERIA. They are characterized by a mainly photosynthetic mode of nutrition; essentially unlimited growth at localized regions of cell divisions (MERISTEMS); cellulose within cells providing rigidity; the absence of organs of locomotion; absence of nervous and sensory systems; and an alternation of haploid and diploid generations. It is a non-taxonomical term most often referring to LAND PLANTS. In broad sense it includes RHODOPHYTA and GLAUCOPHYTA along with VIRIDIPLANTAE.	Plant
D011132	Polyribosomes	A multiribosomal structure representing a linear array of RIBOSOMES held together by messenger RNA; (RNA, MESSENGER); They represent the active complexes in cellular protein synthesis and are able to incorporate amino acids into polypeptides both in vivo and in vitro. (From Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)	Polysomes,Polyribosome,Polysome
D004625	Embryo, Nonmammalian	The developmental entity of a fertilized egg (ZYGOTE) in animal species other than MAMMALS. For chickens, use CHICK EMBRYO.	Embryonic Structures, Nonmammalian,Embryo, Non-Mammalian,Embryonic Structures, Non-Mammalian,Nonmammalian Embryo,Nonmammalian Embryo Structures,Nonmammalian Embryonic Structures,Embryo Structure, Nonmammalian,Embryo Structures, Nonmammalian,Embryo, Non Mammalian,Embryonic Structure, Non-Mammalian,Embryonic Structure, Nonmammalian,Embryonic Structures, Non Mammalian,Embryos, Non-Mammalian,Embryos, Nonmammalian,Non-Mammalian Embryo,Non-Mammalian Embryonic Structure,Non-Mammalian Embryonic Structures,Non-Mammalian Embryos,Nonmammalian Embryo Structure,Nonmammalian Embryonic Structure,Nonmammalian Embryos,Structure, Non-Mammalian Embryonic,Structure, Nonmammalian Embryo,Structure, Nonmammalian Embryonic,Structures, Non-Mammalian Embryonic,Structures, Nonmammalian Embryo,Structures, Nonmammalian Embryonic
D005260	Female		Females
D006657	Histones	Small chromosomal proteins (approx 12-20 kD) possessing an open, unfolded structure and attached to the DNA in cell nuclei by ionic linkages. Classification into the various types (designated histone I, histone II, etc.) is based on the relative amounts of arginine and lysine in each.	Histone,Histone H1,Histone H1(s),Histone H2a,Histone H2b,Histone H3,Histone H3.3,Histone H4,Histone H5,Histone H7
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D012261	Ribonucleoproteins	Complexes of RNA-binding proteins with ribonucleic acids (RNA).	Ribonucleoprotein
D012333	RNA, Messenger	RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.	Messenger RNA,Messenger RNA, Polyadenylated,Poly(A) Tail,Poly(A)+ RNA,Poly(A)+ mRNA,RNA, Messenger, Polyadenylated,RNA, Polyadenylated,mRNA,mRNA, Non-Polyadenylated,mRNA, Polyadenylated,Non-Polyadenylated mRNA,Poly(A) RNA,Polyadenylated mRNA,Non Polyadenylated mRNA,Polyadenylated Messenger RNA,Polyadenylated RNA,RNA, Polyadenylated Messenger,mRNA, Non Polyadenylated