Isolation and characterization of a novel, low abundance hnRNP protein: A0.
Pre-messenger RNA is bound by a variety of proteins to form large heterogeneous nuclear ribonucleoprotein (hnRNP) complexes. As defined by immunoprecipitation and two-dimensional gel electrophoresis, there appear to be more than 20 abundant hnRNP proteins ranging in size from 34 kDa to 120 kDa. One major class, the A/B family, is typified by its characteristic primary structure containing two RNA binding domains followed by a glycine-rich C-terminus. We report the cloning and characterization of a novel, low-abundance member of the A/B family named hnRNP A0. This protein was affinity isolated using a biotinylated RNA probe [G4(AU3)4A] designed to select a 32-kDa protein implicated in mRNA stability in mammalian cells. hnRNP A0 is a basic protein with a predicted mass of 31.7 kDa and an isoelectric point of 10.1. Comparative protease mapping shows that it is not the AUUUA binding protein we intended to clone. A0 is present in hnRNP complexes and is encoded by a gene distinct from that of any previously cloned A/B family member.
Myer
V E
VE
Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, Howard Hughes Medical Institute, Boyer Center for Molecular Medicine, New Haven, Connecticut 06536-0812, USA.
Steitz
J A
JA
D000225:Adenine; D000595:Amino Acid Sequence; D001483:Base Sequence; D002846:Chromatography, Affinity; D003001:Cloning, Molecular; D017931:DNA Primers; D018076:DNA, Complementary; D015870:Gene Expression; D006367:HeLa Cells; D034441:Heterogeneous-Nuclear Ribonucleoproteins; D006801:Humans; D008969:Molecular Sequence Data; D015347:RNA Probes; D012333:RNA, Messenger; D012261:Ribonucleoproteins / Q000032:analysis*; D017386:Sequence Homology, Amino Acid; D014498:Uracil
D017931:DNA Primers; D018076:DNA, Complementary; D034441:Heterogeneous-Nuclear Ribonucleoproteins; D015347:RNA Probes; D012333:RNA, Messenger; D012261:Ribonucleoproteins; D014498:Uracil; D000225:Adenine