The tubby-iike protein 1 (tulp1) gene is a member of the tubby. multigene f
amily which includes tub, tulp1. tulp2 and tulp3. Human and mouse tulp1 gen
es were cloned and mutations in tulp1 have been implicated in retinitis pig
mentosa in man. Here we report on the cDNA cloning of the chicken tulp1 hom
ologue and its protein product deduced from the nucleotide sequence. The ch
icken Tulp1 protein comprises 358 amino acids with a calculated molecular m
ass of 40 kDa. The overall structure of Tub and Tulp proteins. exemplified
by the highly conserved C-terminal domain of 255 amino acids and the signat
ure motif KLACE, is also preserved in chicken Tulp1. Phylogenetic analysis
demonstrates that chicken tulp1 cDNA and protein are closely related to hum
an and mouse tulp1. In addition, chicken tulp1 mRNA is abundantly expressed
in retina similar to tulp1 expression in human and mouse, Two tulp1-specif
ic transcripts of 2 and 3 kb in size were identified that showed differenti
al regulation during embryonic and postnatal development. Finally, tulp1 mR
NA was found to be expressed in chicken erythroid cells and upregulated by
ligand-activated thyroid hormone receptor (TR alpha /c-erbA). (C) 2001 Else
vier Science B.V. All rights reserved.