KXD1, KxDL motif containing 1


Mapping and Structure

KXD1 (NM_029366): 19p13.11, chr19:18,668,572-18,680,197, 11,626 bp.(Human Feb. 2009 Assembly). 5 exons.

Genome Browser and Gene Sorter in UCSC Gene.
Gene ID: 79036 in NCBI Entrez Gene.
KXD1 in GeneCards.



(1)Transcript Variant 1: NM_001171948, 1,592bp, view ORF and the alignment to genomic. This variant (1) represents the longest transcript.
(2)Transcript Variant 2: NM_024069, 1,461bp, view ORF and the alignment to genomic. This variant (2) differs in the 5' UTR compared to variant 1.
(3)Transcript Variant 3: NM_001171949, 1,496bp, view ORF and the alignment to genomic. This variant (3) differs in the 5' UTR compared to variant 1.

Variants 1, 2, and 3 encode the same protein.

Expression Pattern

Tissue specificity: widely expressed in multiple tissues in mouse (Yang, et al).



kxDL motif-containing protein 1 (KXD1) (NP_001165479): 176aa, UniProt: Q9BQD3.


View KXD1 homologous genes and multiple sequence alignment in NCBI Homologene.


(1) Domains predicted by SMART:
a) low complexity: 109 - 128.

(2) Transmembrane domains predicted by SOSUI: None.


(1) Predicted results by ProScan:
a) N-myristoylation site:
132 to 137 GSCDTS.

b) Casein kinase II phosphorylation site:
69 to 72 TLVE.
106 to 109 SFLE.
136 to 139 TSPD.
166 to 169 SQTD.
168 to 171 TDDE.

c) N-glycosylation site:
50 to 53 NLSS.

d) Protein kinase C phosphorylation site:
53 to 55 SAR.
60 to 62 SER.
86 to 88 TLK.

(2) Predicted results of subprograms by PSORT II:
a) N-terminal signal peptide: none
b) KDEL ER retention motif in the C-terminus: none
c) ER membrane retention signals: none
d) VAC possible vacuolar targeting motif: none
6e) Actinin-type actin-binding motif: type 1: none; type 2: none
f) Prenylation motif: none
g) DNA or RNA binding motif: none
h) Tyrosines in the tail: none
i) Dileucine motif in the tail: none.
j) Coils: 65 to 93 residues.

3D Model

No solved structure.

Proteomic Profiling

Computed theoretical MW=19,668Da, pI=4.76.



(1) Process: pigmentation, vesicle-mediated transport.
(2) Protein interaction in BLOC-1.




Interacts with BLOS1 and several other BLOC-1 subunits (Yang, et al). A component of yeast BLOC-1, which is both a Vps21 effector and an adapter for its GAP Msb3. BLOC-1 and Msb3 interacted in vivo(Peter, et al).


Involved in the development of lysosome-related organelles, such as melanosomes and platelet-dense granules.


Allele or SNP

Yang, et al performed mutation screening of the human KXD1 gene in those HPS patients with no mutations with known HPS genes by amplification of genomic DNAs and sequencing. No defects were observed.

SNPs deposited in dbSNP.






(Animal Models)
Mutation in the Kxd1 gene causes a mild form of Hermansky-Pudlak syndrome (Yang, et al).


  1. Peter AT, Lachmann J, Rana M, Bunge M, Cabrera M, Ungermann C. The BLOC-1 complex promotes endosomal maturation by recruiting the Rab5 GTPase-activating protein Msb3. J Cell Biol 2013; 201: 97-111. PMID: 23547030
  2. Yang Q, He X, Yang L, Zhou Z, Cullinane AR, Wei A, Zhang Z, Hao Z, Zhang A, He M, Feng Y, Gao X, Gahl WA, Huizing M, Li W. The BLOS1-interacting protein KXD1 is involved in the biogenesis of lysosome-related organelles. Traffic 2012; 13: 1160-9. PMID: 22554196

Created by Wei Li 06/13/2013