The expression pattern of the murine Hoxa-10 gene and the sequence recognition of its homeodomain reveal specific properties of Abdominal B-like genes.
Homeobox genes of the Abdominal B (AbdB) family constitute a distinct subset of vertebrate Hox genes. Analysis of the murine Hoxa-10 gene, one member of this family, revealed several properties specific to this class. Two transcripts of Hoxa-10, a10-1 and a10-2, encode homeodomain proteins of 55 kDa (399 amino acids) and 16 kDa (96 amino acids), respectively. These proteins have identical homeodomains and C-terminal regions encoded by a common 3' exon but differ significantly in the sizes of their N-terminal regions because of the usage of alternative 5' exons. The 5' exon of the a10-2 form is also present in transcripts of Hoxa-9, the next 3' gene, indicating that splicing can occur between adjacent AbdB Hox genes within a cluster. Both Hoxa-10 transcripts demonstrated identical patterns of expression in the posterior body and proximal limb bud, differentiating them from AbdB morphogenetic and regulatory transcripts and suggesting a role with other AbdB Hox genes in the patterning of these structures. Finally, a binding site selection identified the sequence AA(A/T)TTTTATTAC as the Hoxa-10 homeodomain consensus binding site, with a TTAT core sequence. Preferential recognition of a TTAT core therefore differentiates the AbdB class from Antennapedia (Antp) class gene products which bind a TAAT core. Thus, in vertebrates, structural similarities, coordinate transcriptional regulation, sites of expression, and binding site preferences all serve to distinguish AbdB from Antp Hox genes.
Benson
G V
GV
Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts.
Nguyen
T H
TH
Maas
R L
RL
D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D016384:Consensus Sequence; D004247:DNA / Q000737:chemistry / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D004622:Embryo, Mammalian; D004625:Embryo, Nonmammalian; D015870:Gene Expression; D015723:Gene Library; D005801:Genes, Homeobox; D000080905:Homeobox A10 Proteins; D018398:Homeodomain Proteins; D006801:Humans; D017403:In Situ Hybridization; D051379:Mice / Q000235:genetics*; D008969:Molecular Sequence Data; D005810:Multigene Family; D014176:Protein Biosynthesis; D015183:Restriction Mapping; D014158:Transcription, Genetic; D014714:Vertebrates
D004268:DNA-Binding Proteins; D000080905:Homeobox A10 Proteins; D018398:Homeodomain Proteins; C092119:Hoxa10 protein, mouse; D004247:DNA