NPHP1
Developmental stage
During in vitro ciliogenesis translocalizes from the cytoplasm to the ciliary transition zone during epithelial cell polarization.
Domain
The SH3 domain mediates the stable interaction with Cas.
Function
Together with BCAR1 it may play a role in the control of epithelial cell polarity (By similarity). Involved in the organization of apical junctions in kidney cells together with NPHP4 and RPGRIP1L/NPHP8 (By similarity). Does not seem to be strictly required for ciliogenesis (By similarity). Seems to help to recruit PTK2B/PYK2 to cell matrix adhesions, thereby initiating phosphorylation of PTK2B/PYK2 and PTK2B/PYK2-dependent signaling (By similarity). May play a role in the regulation of intraflagellar transport (IFT) during cilia assembly. Required for normal retina development (By similarity). In connecting photoreceptor cilia influences the movement of some IFT proteins such as IFT88 and WDR19. Involved in spermatogenesis (By similarity).
Involvement in disease
Nephronophthisis 1
NPHP1
An autosomal recessive inherited disease characterized by anemia, polyuria, polydipsia, isosthenuria and death in uremia. Symmetrical destruction of the kidneys involving both tubules and glomeruli occurs. The underlying pathology is a chronic tubulo-interstitial nephropathy with characteristic tubular basement membrane thickening and medullary cyst formation. Associations with extrarenal symptoms, especially ocular lesions, are frequent. The age at death ranges from about 4 to 15 years.
None
The disease is caused by variants affecting the gene represented in this entry.
Senior-Loken syndrome 1
SLSN1
A renal-retinal disorder characterized by progressive wasting of the filtering unit of the kidney (nephronophthisis), with or without medullary cystic renal disease, and progressive eye disease. Typically this disorder becomes apparent during the first year of life.
None
The disease is caused by variants affecting the gene represented in this entry.
Joubert syndrome 4
JBTS4
A disorder presenting with cerebellar ataxia, oculomotor apraxia, hypotonia, neonatal breathing abnormalities and psychomotor delay. Neuroradiologically, it is characterized by cerebellar vermian hypoplasia/aplasia, thickened and reoriented superior cerebellar peduncles, and an abnormally large interpeduncular fossa, giving the appearance of a molar tooth on transaxial slices (molar tooth sign). Additional variable features include retinal dystrophy and renal disease. Joubert syndrome type 4 is a phenotypically mild form.
None
The disease is caused by variants affecting the gene represented in this entry.
Post-translational modifications
Phosphorylation by CK2 is required for the interaction with PACS1 and the targeting to the base region of cilia.
Sequence Similarities
Belongs to the nephrocystin-1 family.
Tissue Specificity
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 (at protein level) (PubMed:16308564). Expressed in the renal collecting duct (at protein level) (PubMed:18477472).
Cellular localization
- Cell junction
- Cell junction
- Adherens junction
- Cell projection
- Cilium
- Cytoplasm
- Cytoskeleton
- Cilium axoneme
- Cell junction
- Tight junction
- In the retinal photoreceptor cell layer, localizes at the connecting cilium (By similarity). Colocalizes with E-cadherin and BCAR1 at or near the cell-cell adherens junctions (By similarity). Localized to respiratory cilia axoneme (PubMed:16308564, PubMed:16885411). Localized to the transition zone of respiratory cilia (PubMed:16885411). Localized to the transition zone of photoreceptor-connecting cilia and renal monocilia (By similarity). In cultured renal cells, it localizes diffusely in the cytoplasm but, as cells approach confluence, it accumulates at basolateral tight junctions (By similarity).
Alternative names
NPH1, NPHP1, Nephrocystin-1, Juvenile nephronophthisis 1 protein