---
pmid: '25449265'
title: Basolateral sorting of the Mg²⁺ transporter CNNM4 requires interaction with
  AP-1A and AP-1B.
authors:
- Hirata Y
- Funato Y
- Miki H
journal: Biochem Biophys Res Commun
year: '2014'
full_text_available: false
doi: 10.1016/j.bbrc.2014.10.138
pubmed_publication_types:
- Journal Article
- Research Support, Non-U.S. Gov't
publication_type: PRIMARY_RESEARCH
---

# Basolateral sorting of the Mg²⁺ transporter CNNM4 requires interaction with AP-1A and AP-1B.
**Authors:** Hirata Y, Funato Y, Miki H
**Journal:** Biochem Biophys Res Commun (2014)
**DOI:** [10.1016/j.bbrc.2014.10.138](https://doi.org/10.1016/j.bbrc.2014.10.138)

## Abstract

1. Biochem Biophys Res Commun. 2014 Dec 12;455(3-4):184-9. doi:
10.1016/j.bbrc.2014.10.138. Epub 2014 Nov 10.

Basolateral sorting of the Mg²⁺ transporter CNNM4 requires interaction with
AP-1A and AP-1B.

Hirata Y(1), Funato Y(2), Miki H(3).

Author information:
(1)Department of Cellular Regulation, Research Institute for Microbial Diseases,
Osaka University, 3-1 Yamadaoka, Suita, Osaka 565-0871, Japan; Laboratory of
Health Chemistry, Graduate School of Pharmaceutical Sciences, Tohoku University,
6-3 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8578, Japan.
(2)Department of Cellular Regulation, Research Institute for Microbial Diseases,
Osaka University, 3-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
(3)Department of Cellular Regulation, Research Institute for Microbial Diseases,
Osaka University, 3-1 Yamadaoka, Suita, Osaka 565-0871, Japan. Electronic
address: hmiki@biken.osaka-u.ac.jp.

Ancient conserved domain protein/cyclin M (CNNM) 4 is an evolutionarily
conserved Mg(2+) transporter that localizes at the basolateral membrane of the
intestinal epithelia. Here, we show the complementary importance of clathrin
adaptor protein (AP) complexes AP-1A and AP-1B in basolateral sorting of CNNM4.
We first confirmed the basolateral localization of both endogenous and
ectopically expressed CNNM4 in Madin-Darby Canine Kidney cells, which form
highly polarized epithelia in culture. Single knockdown of μ1B, a
cargo-recognition subunit of AP-1B, did not affect basolateral localization, but
simultaneous knockdown of the μ1A subunit of AP-1A abrogated localization.
Mutational analyses showed the importance of three conserved dileucine motifs in
CNNM4 for both basolateral sorting and interaction with μ1A and μ1B. These
results imply that CNNM4 is sorted to the basolateral membrane by the
complementary function of AP-1A and AP-1B.

Copyright © 2014 Elsevier Inc. All rights reserved.

DOI: 10.1016/j.bbrc.2014.10.138
PMID: 25449265 [Indexed for MEDLINE]