PKHDL1, a homolog of the autosomal recessive polycystic kidney disease gene, encodes a receptor with inducible T lymphocyte expression

摘要: Autosomal-recessive polycystic kidney disease (ARPKD) is caused by mutation to a large gene, PKHD1, encoding putative receptor protein, fibrocystin. We have identified, through analysis of human genomic sequence, PKHD1 homolog, PKHDL1, in chromosome region 8q23. The PKHDL1 transcript 13081 bp was amplified as 16 fragments and sequenced; the sequence murine ortholog, Pkhdl1 (chromosome 15B3) also determined. contains 78 exons, covers � 168 kb encodes fibrocystin-L. Screening ARPKD patients with no mutations revealed several variants but clear mutations, making it unlikely that ARPKD-associated. Human fibrocystin-L predicted be protein (4243 aa; 466 kDa) signal peptide, single transmembrane domain short cytoplasmic tail. Fibrocystin-L homologous fibrocystin throughout most extracellular overall identity 25.0% similarity 41.5%. has domains similar 14 copies TIG two regions significant homology TMEM2. Genomic identified other full-length homologs humans, mice or sequenced organisms. Fugu fish ortholog fibrocystin, suggesting newly may ancestral form. are widely expressed at low level tissues only detected blood-derived cell-lines. Low expression many primary immune cell subtypes up-regulated specifically T lymphocytes, following activation signals, role cellular immunity.