PLANT PHYSIOLOGY , Vol 103, Issue 2 525-533, Copyright © 1993 by American Society of Plant Biologists
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MOLECULAR BIOLOGY AND GENE REGULATION |
Molecular Characterization of PAB2, a Member of the Multigene Family Coding for Poly(A)-Binding Proteins in Arabidopsis thaliana
P. Hilson, K. L. Carroll and P. H. Masson
Laboratory of Genetics, University of Wisconsin, Madison, Wisconsin 53706 (P.H., K.L.C., P.H.M.);
The poly(A) tail of eukaryotic mRNAs associates with poly(A)-binding (PAB)
proteins whose role in mRNA translation and stability is being intensively
investigated. Very little is known about the structure and function of the
PAB genes in plants. We have cloned multiple PAB-related sequences from
Arabidopsis thaliana. Results suggest that PAB proteins are encoded by a
multigene family. One member of this family (PAB2) is expressed in root and
shoot tissues. The complete nucleotide sequence of PAB2 was determined.
Study of the predicted PAB2 protein reveals a similarity in structure among
vertebrate, insect, yeast, and plant PAB proteins. All contain two highly
conserved domains: an amino-terminal sequence formed by four RNA
recognition motifs and an uncharacterized carboxyl-terminal region of 69 to
71 amino acids. Possible roles for the carboxyl-terminal conserved domain
are discussed in view of recently published data concerning the structure
and function of PAB proteins.