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ADAPTOR-RELATED PROTEIN COMPLEX 3, SIGMA-1 SUBUNIT; AP3S1

Alternative titles; symbols

CLATHRIN-ASSOCIATED/ASSEMBLY/ADAPTOR PROTEIN, SMALL 3, 22-KD; CLAPS3
CLATHRIN ADAPTOR COMPLEX AP3, SIGMA-3A SUBUNIT

Gene map locus 12p13.2-p13.1

TEXT

CLONING

From a human fetal brain cDNA library, Watanabe et al. (1996) isolated a gene encoding a peptide homologous to clathrin-adaptor small chains in rat, mouse, and yeast. The AP3S1 gene, which they designated CLAPS3 (for clathrin-associated/assembly/adaptor protein, small 3, 22-kD), contains an open reading frame of 579 bp encoding 193 amino acids. Northern blot analysis revealed expression of a 1.35-kb transcript in all human tissues examined.

GENE FUNCTION

Dell'Angelica et al. (1997) found that CLAPS3, which they designated sigma-3A, is part of a large complex, AP3, that appears to be a ubiquitously expressed adaptor-like complex involved in protein sorting.

Using a yeast 2-hybrid assay, Lefrancois et al. (2004) determined that the ear domain of the AP3 delta subunit (AP3D1; 607246) interacts with both isoforms of the sigma-3 subunit, sigma-3A and sigma-3B (AP3S2; 602416). An extended C-terminal segment of sigma-3 was necessary for the interaction with the delta subunit. The delta-sigma-3 interaction interfered with the binding of AP3 to ARF (see 103180), but not with its binding to dileucine-based sorting signals. As a consequence, the delta subunit ear inhibited the recruitment of AP3 to membranes both in vitro and in vivo and impaired the sorting of lysosomal membrane proteins.

MAPPING

Watanabe et al. (1996) mapped the AP3S1 gene to 12p13.2-p13.1 by fluorescence in situ hybridization.

REFERENCES

1. Dell'Angelica, E. C.; Ohno, H.; Ooi, C. E.; Rabinovich, E.; Roche, K. W.; Bonifacino, J. S. :

AP-3: an adaptor-like protein complex with ubiquitous expression. EMBO J. 16: 917-928, 1997.
PubMed ID : 9118953

2. Lefrancois, S.; Janvier, K.; Boehm, M.; Ooi, C. E.; Bonifacino, J. S. :

An ear-core interaction regulates the recruitment of the AP-3 complex to membranes. Dev. Cell 7: 619-625, 2004.
PubMed ID : 15469849

3. Watanabe, T. K.; Shimizu, F.; Nagata, M.; Takaichi, A.; Fujiwara, T.; Nakamura, Y.; Takahashi, E.; Hirai, Y. :

Cloning, expression pattern and mapping to 12p13.2-p13.1 of CLAPS3, a gene encoding a novel clathrin-adaptor small chain. Cytogenet. Cell Genet. 73: 214-217, 1996.
PubMed ID : 8697810

CONTRIBUTORS

Patricia A. Hartz - updated : 11/22/2004
Rebekah S. Rasooly - updated : 3/5/1998

CREATION DATE

Victor A. McKusick : 11/15/1996

EDIT HISTORY

wwang : 8/31/2006
mgross : 11/22/2004
psherman : 1/5/1999
psherman : 1/4/1999
alopez : 4/8/1998
alopez : 4/8/1998
alopez : 3/5/1998
alopez : 1/8/1998
mark : 11/17/1996
mark : 11/15/1996

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