Cloning and characterization of freac-9 (FKHL17), a novel kidney-expressed human forkhead gene that maps to chromosome 1p32-p34.
We describe the cloning of a near full-length cDNA of 4258 nucleotides encoding freac-9 (HGMW-approved symbol FKHL17), a novel human forkhead gene. The 5' untranslated region is unusual since it is very long, 2127 nucleotides, and contains 15 upstream AUG codons. Hybridization to a panel consisting of RNA derived from 50 different tissues showed that freac-9 is transcribed exclusively in the kidney. The kidney-derived cell lines COS-7 and 293 are shown to express freac-9. A combination of fluorescence in situ hybridization and somatic cell hybrids localizes freac-9 to the chromosomal region of 1p32-p34. The conceptual translation product predicts a protein of 372 amino acids with an N-terminal domain rich in acidic amino acids and with a high likelihood of forming an amphipatic helix, a DNA binding forkhead domain, and a C-terminal region that has a high probability of forming an amphipatic beta-sheet. The amino acid sequence of the DNA binding forkhead motif of FREAC-9 is identical to that of another forkhead protein, FREAC-4, whereas 12 substitutions are present at the nucleotide level. There are no similarities in regions outside of the DNA binding domains of FREAC-9 and FREAC-4 and since freac-4 maps to a different chromosome (5q12-q13) it is likely that an evolutionary selection has acted to maintain identical DNA binding domains between these two kidney expressed transcription factors.
Ernstsson
S
S
Department of Molecular Medicine, Karolinska Hospital, Stockholm, Sweden.
Betz
R
R
Lagercrantz
S
S
Larsson
C
C
Ericksson
S
S
Cederberg
A
A
Carlsson
P
P
Enerbäck
S
S
D000595:Amino Acid Sequence; D001483:Base Sequence; D002874:Chromosome Mapping; D002878:Chromosomes, Human, Pair 1 / Q000235:genetics*; D003001:Cloning, Molecular; D005796:Genes / Q000235:genetics; D006801:Humans; D007668:Kidney / Q000737:chemistry*; D008969:Molecular Sequence Data; D009928:Organ Specificity; D012333:RNA, Messenger / Q000032:analysis; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid
D012333:RNA, Messenger