High impact information on CyIIb

• The CyI, CyIIa, and CyIIb genes are transcribed at a moderate rate that does not vary significantly during development [1].
• CyI and CyIIb are expressed in all lineages at some point in embryogenesis, but confined mainly to oral ectoderm and portions of the gut of the pluteus larva [2].
• As is the case with the other sea urchin cytoskeletal actin genes previously studied, the CyIIb and CyIIIb genes contain two introns that interrupt the coding DNA following codon 121 and within codon 204 [3].
• Nucleotide sequence comparisons of 5'-flanking region and intron DNA, however, indicate greater similarity between the CyI and CyIIb genes than the CyIIa gene that separates them, suggestive of a potential gene conversion event between the flanking genes in the CyI-CyIIa-CyIIb linkage [3].
• This is in contrast to strong protein binding to the CyIIb SRE [4].

Biological context of CyIIb

• The similarity between CyIIa and CyI (and CyIIb) upstream sequences was limited and included a consensus octamer sequence, serum response element (SRE) and some short sequences within the proximal promoter region [4].
• The sequences corresponding to regions upstream of the ATG and transcription start site of the CyIIa cytoplasmic actin gene of the sea urchin Strongylocentrotus purpuratus were determined and compared to the genomically linked CyI and CyIIb actin genes [4].

Other interactions of CyIIb

• Actin genes CyI, CyIIa, CyIIb, and M are expressed in both adult and embryonic tissues, giving rise to transcripts 2.1-2.2 kb in length [5].

References