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FLASH GENE

Symbol

TTC21B

contributors: mct - updated : 31-05-2019

HGNC name	tetratricopeptide repeat domain 21B
HGNC id	25660

FLASH GENE DNA RNA EXPRESSION PROTEIN DISORDER ANIMAL & CELL MODELS

Corresponding disease	ATD4 asphyxiating thoracic dystrophy 4 NPHP12 nephronophthisis 12
Location	2q24.3      Physical location : 166.730.453 - 166.810.348
Synonym name	TPR repeat protein 21B
	putative protein product of Nbla10696
	tetratricopeptide repeat-containing hedgehog modulator-1
	retrograde intraflagellar transport protein 139
Synonym symbol(s)	Nbla10696, FLJ11457, THM1, IFT139, ATD4, SRTD4, JBTS11, NPHP12, Nbla10696

DNA

TYPE	functioning gene
STRUCTURE	79.90 kb     29 Exon(s)

MAPPING

cloned

Y

linked

Y

status

provisional

RNA

TRANSCRIPTS	type	messenger

identification nb exons type bp product Protein kDa AA specific expression Year Pubmed NM_024753 29 - 4916 NP_079029 150.9 1316 - 2011 21068128

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 Reproductive male system male genital tract seminiferous tubule     Homo sapiens   male system testis       Homo sapiens Visual eye retina       Homo sapiens

cells

System Cell Pubmed Species Stage Rna symbol Reproductive ciliated cell Homo sapiens Reproductive Leydig cell Homo sapiens Visual cone photoreceptor Homo sapiens Visual rod photoreceptor Homo sapiens

cell lineage

cell lines

fluid/secretion

at STAGE

PROTEIN

PHYSICAL PROPERTIES

STRUCTURE

motifs/domains

several tetratricopeptide (TPR) domains that seem important for ciliary function by virtue of their enrichment in the ciliary proteome and photoreceptor sensory cilium proteome

HOMOLOGY

intraspecies

paralog to TTC21A

Homologene

FAMILY

CATEGORY

transcription factor

SUBCELLULAR LOCALIZATION	intracellular
	intracellular,cytoplasm,cytoskeleton,microtubule
	intracellular,cytoplasm,cytoskeleton,intermed filament
	intracellular,nucleus,chromatin/chromosome
text	localizes to cilia

basic FUNCTION	axonemal protein that is required for retrograde intraflagellar transport
	negatively modulates potentially sonic hedgehog signal transduction and affects retrograde intraflagellar transport in cilia
	required to restrict sonic hedgehog activity in the developing mouse forebrain
	novel photoreceptor sensory cilium protein and is required for normal cilia formation in primary and photoreceptor sensory cilia
	may be required for normal photoreceptor development
	contributes both causal and modifying alleles across the ciliopathy spectrum
	encodes a component of the intraflagellar transport-A complex
	is required for proper primary cilia form and function, and is primarily thought to restrict SHH signaling
	TTC21B expression is required for Bergmann glia structure and signaling in the developing cerebellum, and in some contexts, augments rather than attenuates SHH signaling

CELLULAR PROCESS

PHYSIOLOGICAL PROCESS

PATHWAY

metabolism

signaling

a component

IFT-A protein complex consists of IFT43, WDR35, IFT122, TTC21B, IFT140 and WDR19 and is associated with THM1 and TULP3

INTERACTION

DNA

RNA

small molecule

protein	is dispensable for IFT-A assembly but essential for retrograde trafficking of IFT-A, IFT-B, and GPCRs
	interacts with the IFT-A complex via the IFT122 subunit and is accumulated at the distal tip in the absence of an IFT-A subunit TTC21B

cell & other

REGULATION

ASSOCIATED DISORDERS

corresponding disease(s)

ATD4 , NPHP12

Other morbid association(s)

Type Gene Modification Chromosome rearrangement Protein expression Protein Function constitutional germinal mutation       cause both isolated nephronophthisis and syndromic Jeune asphyxiating thoracic dystrophy

Susceptibility

Variant & Polymorphism

Candidate gene

Marker

Therapy target

ANIMAL & CELL MODELS

	ciliary defects seen in the Ttc21b murine mutant extend to the embryonic brain, adding forebrain development to the spectrum of tissues affected by defects in ciliary physiology
	in mouse Thm1-mutant ciliary defect diminishes sensitivity to feeding signals, which alters appetite regulation and leads to hyperphagia, obesity and metabolic disease