GrassTFDB :: Browse Family::Sorghum

Displaying CCAAT-HAP2 Family from Sorghum


The CCAAT motif is found in the promoters of many eukaryotic genes. In yeast a single complex of three proteins termed HAP2 HAP3 and HAP5 binds to this sequence and in mammals the three components of the equivalent complex (called variously NF-Y CBF or CP1) are also represented by single genes. Here we report the presence of multiple genes for each of the components of the CCAAT-binding complex HAP2 35 from Arabidopsis. Three independent Arabidopsis HAP subunit 2 (AtHAP2) cDNAs were cloned by functional complementation of a yeast hap2 mutant and two independent forms each of AtHAP3 and AtHAP5 cDNAs were detected in the expressed sequence tag database. Additional homologs (two of AtHAP3 and one of AtHAP5) have been identified from available Arabidopsis genomic sequences. Northern-blot analysis indicated ubiquitous expression for each AtHAP2 and AtHAP5 cDNA in a range of tissues whereas expression of each AtHAP3 cDNA was under developmental and/or environmental regulation. The unexpected presence of multiple forms of each HAP homolog in Arabidopsis compared with the single genes in yeast and vertebrates suggests that the HAP235 complex may play diverse roles in gene transcription in higher plants.

Protein Name
accepted / suggested
Gene Locus Synonym/
Gene Name
Clone in TFome Genome Browser
SbCA2P1 Sb01g011220 View in Browser
SbCA2P2 Sb01g013430 View in Browser
SbCA2P3 Sb01g032710 View in Browser
SbCA2P4 Sb01g045500 View in Browser
SbCA2P5 Sb02g003320 View in Browser
SbCA2P6 Sb02g038960 View in Browser
SbCA2P7 Sb04g034760 View in Browser
SbCA2P8 Sb08g021370 View in Browser
SbCA2P9 Sb08g021910 View in Browser