The Arabidopsis genome possesses a number of sequences that are predicted to encode proteins that are similar to mammalian and yeast polyadenylation factor subunits. One of these resides on chromosome V and has the potential to encode a polypeptide related to the 100 kDa subunit of the mammalian cleavage and polyadenylation specificity factor (CPSF). This gene encodes a ca. 2400 nucleotide mRNA that in turn can be translated to yield a polypeptide that is 39% identical to the mammalian CPSF100 protein. Antibodies raised against the Arabidopsis protein recognized distinctive polypeptides in nuclear extracts prepared from pea and wheat germ, consistent with the hypothesis that the Arabidopsis protein is resident in a nuclear polyadenylation complex. Interestingly, the Arabidopsis CPSF100 was found to interact with a portion of a nuclear poly(A) polymerase. This interaction was attributable to a 60 amino acid domain in the CPSF100 polypeptide and the N-terminal 220 amino acids of the poly(A) polymerase. An analogous interaction has yet to be described in other eukaryotes. The interaction with PAP thus indicates that the plant CPSF100 polypeptide is likely part of the 3′-end processing machinery, but suggests that this complex may function differently in plants than it does in mammals and yeast.
|Number of pages||12|
|Journal||Plant Molecular Biology|
|State||Published - Feb 2003|
Bibliographical noteFunding Information:
We thank Carol Von Lanken for excellent technical assistance and suggestions regarding the manuscript. We are grateful to Dr Brenton Graveley for suggestions and the gift of the EST clones bearing the Arabidopsis CPSF100-related sequences. This work was supported by a grant from the USDA (NRI grant 95-37301-2041).
- Poly(A) polymerase
- RNA processing
- mRNA 3′-end formation
ASJC Scopus subject areas
- Agronomy and Crop Science
- Plant Science