NPHP1 cDNA Clone – Nephronophthisis 1 (Juvenile) (Human)

This gene encodes a protein with src homology domain 3 (SH3) patterns. This protein interacts with Crk-associated substrate, and it appears to function in the control of cell division, as well as in cell-cell and cell-matrix adhesion signaling, likely as part of a multifunctional complex localized in actin- and microtubule-based structures. Mutations in this gene cause familial juvenile nephronophthisis type 1, a kidney disorder involving both tubules and glomeruli. Defects in this gene are also associated with Senior-Loken syndrome type 1, also referred to as juvenile nephronophthisis with Leber amaurosis, which is characterized by kidney and eye disease, and with Joubert syndrome type 4, which is characterized by cerebellar ataxia, oculomotor apraxia, psychomotor delay and neonatal breathing abnormalities, sometimes including retinal dystrophy and renal disease. Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jul 2008]

NPHP1: Together with BCAR1 it may play a role in the control of epithelial cell polarity. Involved in the organization of apical junctions in kidney cells together with NPHP4 and RPGRIP1L/NPHP8. Does not seem to be strictly required for ciliogenesis. Seems to help to recruit PTK2B/PYK2 to cell matrix adhesions, thereby initiating phosphorylation of PTK2B/PYK2 and PTK2B/PYK2-dependent signaling. May play a role in the regulation of intraflagellar transport (IFT) during cilia assembly. Required for normal retina development. In connecting photoreceptor cilia influences the movement of some IFT proteins such as IFT88 and WDR19. Involved in spermatogenesis. Interacts with BCAR1, PTK2B/PYK2 and tensin. Interacts with INVS and NPHP3. Interacts with PACS1; the interaction is dependent on NPHP1 phosphorylation by CK2. Interatcs with KIF7. Interacts with AHI1 and TNK2. Interacts with NPHP4 in a complex containing NPHP1, NPHP4 and RPGRIP1L. Interacts with IQCB1; the interaction likely requires additional interactors. Widespread expression, with highest levels in pituitary gland, spinal cord, thyroid gland, testis, skeletal muscle, lymph node and trachea. Weakly expressed in heart, kidney and pancreas. Expressed in nasal epithelial cells. Belongs to the nephrocystin-1 family. 4 isoforms of the human protein are produced by alternative splicing.

Protein type: Cell adhesion

Chromosomal Location of Human Ortholog: 2q13

Cellular Component: cytosol; intercellular junction; photoreceptor connecting cilium

Molecular Function: protein binding

Biological Process: cell projection organization and biogenesis; excretion; retina development in camera-type eye; spermatid differentiation

Disease: Joubert Syndrome 4; Nephronophthisis 1; Senior-loken Syndrome 1