TOBFAC: The database of tobacco transcription factors
Family: AS2
Minimum number of tobacco AS2 genes: 75
Count of tobacco AS2 sequences: 91
Pfam accession: PF03195 DUF260
The LOB domain contains conserved blocks of amino acids that identify the LBD gene family. In particular, a conserved C-x(2)-C-x(6)-C-x(3)-C motif, which is defining feature of the LOB domain, is present in all LBD proteins. It is possible that this motif forms a new zinc finger.
The lateral organ boundaries (LOB) gene is expressed at the adaxial base of initiating lateral organs and encodes a plant-specific protein of unknown function. The N-terminal one half of the LOB protein contains a conserved approximately 100-amino acid domain (the LOB domain) that is present in 42 other Arabidopsis thaliana proteins and in proteins from a variety of other plant species. Genes encoding LOB domain (LBD) proteins are expressed in a variety of temporal- and tissue-specific patterns, suggesting that they may function in diverse processes.
The ASYMMETRIC LEAVES2 (AS2) gene of Arabidopsis thaliana is involved in the establishment of the leaf venation system, which includes the prominent midvein, as well as in the development of a symmetric lamina. The gene product also represses the expression of class 1 knox homeobox genes in leaves. We have characterized the AS2 gene, which appears to encode a novel protein with cysteine repeats (designated the C-motif) and a leucine-zipper-like sequence in the amino-terminal half of the primary sequence. The Arabidopsis genome contains 42 putative genes that potentially encode proteins with conserved amino acid sequences that include the C-motif and the leucine-zipper-like sequence in the amino-terminal half. Thus, the AS2 protein belongs to a novel family of proteins that we have designated the AS2 family. Members of this family except AS2 also have been designated ASLs (AS2-like proteins). Transcripts of AS2 were detected mainly in adaxial domains of cotyledonary primordia. Green fluorescent protein-fused AS2 was concentrated in plant cell nuclei. Overexpression of AS2 cDNA in transgenic Arabidopsis plants resulted in upwardly curled leaves, which differed markedly from the downwardly curled leaves generated by loss-of-function mutation of AS2. Our results suggest that AS2 functions in the transcription of a certain gene(s) in plant nuclei and thereby controls the formation of a symmetric flat leaf lamina and the establishment of a prominent midvein and other patterns of venation.
Iwakawa H, Ueno Y, Semiarti E, Onouchi H, Kojima S, Tsukaya H, Hasebe M, Soma T, Ikezaki M, Machida C, Machida Y. The ASYMMETRIC LEAVES2 gene of Arabidopsis thaliana, required for formation of a symmetric flat leaf lamina, encodes a member of a novel family of proteins characterized by cysteine repeats and a leucine zipper. Plant Cell Physiol. 2002 May;43(5):467-78. PMID: 12040093
Number of contigs: 85
Number of singlets: 8
Number of N terminal – 16
Number of C terminal – 21
Number of full – 54
Total minimum number – 75
| Family | Genbank ID | Name |
Paul J Rushton
Marta T. Bokowiec
Xianfeng (Jeff) Chen
Thomas (Tom) W Laudeman
Jennifer F. Brannock
Michael P. Timko