Plant Molecular Biology 40: 579–590, 1999.
© 1999 Kluwer Academic Publishers. Printed in the Netherlands.
Early elicitor induction in members of a novel multigene family coding for
highly related RING-H2 proteins in Arabidopsis thaliana
ul E. Salinas-Mondrag
on, Cristina Garcidueñas-Piña and Plinio Guzm
Departamento de Ingenier´ıa Gen´etica de Plantas, Centro de Investigaci´on y de Estudios Avanzados del IPN,
Unidad Irapuato, Apartado Postal 629, Irapuato, Gto., 36500 M´exico (
author for correspondence)
Received 17 November 1998; accepted in revised form 3 March 1999
Key words: early response, cellulase, gene family, mRNA stability, RING ﬁnger, transmembrane domain
We describe the identiﬁcation and structural characterization of a novel family of Arabidopsis genes related to
ATL2 which encode a variant of the RING zinc ﬁnger domain, known as RING-H2. Analysis of genes selected by
us andofsequencesfromArabidopsisstored in databases permitted the prediction of severalRING-H2proteinsthat
contain highly homologous RING domains. The ATL gene family is represented by ﬁfteen sequences that contain,
in addition to the RING, a transmembrane domain which is located in most of them towards the N-terminal end.
Transgenic Arabidopsis seedlings carrying the ATL2 promoter fused to the GUS reporter gene revealed that the
expression of ATL2 is rapidly induced after exposure to chitin or inactivated crude cellulase preparations. Rapid
induction of transcript accumulation of another member of the ATL family was also observed under the same
conditions. These results suggest that some ATLs may be involved in the early stages of the defense response
triggered in plants in response to pathogen attack.
Zinc ﬁngers are autonomouslyfolded protein domains
in which cysteine and histidine residues are used to
coordinateone or more zinc ions (Bergand Shi, 1996).
Theyhave been found as part of proteins which partic-
ipate in the regulation of many aspects of growth and
development in eukaryotic organisms. Several classes
of zinc-ﬁnger domains have been identiﬁed; most of
them form part of the nucleic acid-binding domain
of many proteins, often cited examples being TFI-
IIA, the glucocorticoid receptor, GAL4 and GATA-1
proteins (Berg and Shi, 1996; Mackay and Cross-
ley, 1988). Zinc-ﬁnger domains are also implicated in
protein/protein interactions. One example is the LIM
domain that is constituted by 2 distinct zinc ﬁngers and
is found in proteins with diverse functions (Schmei-
chel and Beckerle, 1994). Another domain that has
The nucleotide sequence data reported will appear in the
EMBL, GenBank and DDBJ Nucleotide Sequence Databases un-
der the accession numbers AF132013 (ATL3), AF132014 (ATL4),
AF132015 (ATL5) and AF132016 (ATL6).
been suggested to be involved in protein/protein in-
teractions is the C3HC4, also known as the RING
ﬁnger (Really Interesting New Gene) (Saurin et al.,
1996). The RING ﬁnger motif is found in numer-
ous proteins present in a wide range of organisms.
It is encoded in regulatory proteins including viral
transcription factors, oncoproteins and components of
signal transduction pathways and in proteins involved
in DNA repair and recombination (Saurin et al., 1996).
This domain differs from other zinc-binding domains
in the overall primary amino acid sequence, in the
arrangement of the residues which serve as ligands for
zinc ions and in the tertiary structure it acquires upon
folding (Saurin et al., 1996).
Despite being widely distributed and present in
gene products which play major roles during cell
growth and differentiation, the molecular function of
the RING-ﬁnger domain has not yet been well estab-
lished. It has been inferred that the structure of RING
may vary according to the sequences surrounding it,
thereby suggesting that this zinc ﬁnger might carry
out diverse molecular functions (Borden et al., 1995;