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FLASH GENE

Symbol

CLDN9

contributors: mct/npt - updated : 11-04-2023

HGNC name	claudin 9
HGNC id	2051

FLASH GENE DNA RNA EXPRESSION PROTEIN DISORDER ANIMAL & CELL MODELS

DNA

TYPE	chromosome region
STRUCTURE	1.58 kb     1 Exon(s)

10 Kb 5' upstream gene genomic sequence study

MAPPING

cloned

Y

linked

N

status

provisional

RNA

TRANSCRIPTS	type	messenger

identification nb exons type bp product Protein kDa AA specific expression Year Pubmed NM_020982 1 - 1583 NP_066192 22.7 217 - 2019 31175426

EXPRESSION

Type

expressed in	(based on citations)
organ(s)	System Organ level 1 Organ level 2 Organ level 3 Organ level 4 Level Pubmed Species Stage Rna symbol Digestive liver       highly Endocrine neuroendocrine pituitary     highly Homo sapiens Hearing/Equilibrium ear inner cochlea       ear inner vestibule

cells

System Cell Pubmed Species Stage Rna symbol Blood/Hematopoietic monocyte Hearing / Equilibrium cochlea cell Hearing / Equilibrium stereocilia

cell lineage

cell lines

fluid/secretion

at STAGE

PROTEIN

PHYSICAL PROPERTIES

STRUCTURE

motifs/domains

four putative transmembrane segments

HOMOLOGY

Homologene

FAMILY

claudin family

CATEGORY

adhesion , structural protein

SUBCELLULAR LOCALIZATION	plasma membrane,junction,tight
text	integral membrane protein and constituent of epithelial bicellular tight junctions (TJs)

basic FUNCTION	tight junction specific obliteration of the intercellular space
	creating charge specific channels in the paracellular space
	able to mediate HCV entry just as efficiently as CLDN1 and able to mediate the entry of HCV into target cells (Zheng 2007)
	with CLDN1 and CLDN6, are entry cofactors for hepatitis C virus HCV (Meertens 2008)
	required for the preservation of sensory cells in the hearing organ because claudin-9–defective tight junctions fail to shield the basolateral side of hair cells from the K+-rich endolymph (Nakano 2009)
	its ion barrier function is essential in the cochlea, but appears to be dispensable in other organs (Nakano 2009)
	essential role for claudin-9 in promoting lung cancer metastasis
	likely CLDN9 plays a role in the formation of TJs associated with dense cytoplasmic plaques

CELLULAR PROCESS

PHYSIOLOGICAL PROCESS

PATHWAY

metabolism

signaling

a component	major structural components of tight junction (TJ) strands
	is a major component of TJs in the Folliculo-stellate (FS) cells

INTERACTION

DNA

RNA

small molecule

protein

NDRG1 is important to maintain the integrity of airway epithelial barrier through CLDN9 expression

cell & other

REGULATION

ASSOCIATED DISORDERS

corresponding disease(s)

DFNB116

Other morbid association(s)

Type Gene Modification Chromosome rearrangement Protein expression Protein Function tumoral     --other   aberrant CLDN9 expression is a predictor of poor prognosis for endometrial cancer

Susceptibility

Variant & Polymorphism

Candidate gene
Marker	could potentially be used as a diagnostic and/or prognostic marker for subtypes of pituitary adenomas (
	CLDN9 may be an important biomarker for invasive pituitary oncocytomas
Therapy target
	System Type Disorder Pubmed tumor     could potentially be used as an immunotherapy target for subtypes of pituitary adenomas

ANIMAL & CELL MODELS

ENU–induced mouse mutant (nmf329) with Claudin 9 mutation exhibits recessively inherited deafness (Nakano 2009)