TY - JOUR
T1 - Tyrosine-based membrane protein sorting signals are differentially interpreted by polarized Madin-Darby canine kidney and LLC-PK1 epithelial cells
AU - Roush, Denise L.
AU - Gottardi, Cara J.
AU - Naim, Hussein Y.
AU - Roth, Michael G.
AU - Caplan, Michael J.
PY - 1998/10/9
Y1 - 1998/10/9
N2 - Tyrosine-dependent sequence motifs are implicated in sorting membrane proteins to the basolateral domain of Madin-Darby canine kidney (MDCK) cells. We find that these motifs are interpreted differentially in various polarized epithelial cell types. The H,K-ATPase β subunit, which contains a tyrosine- based motif in its cytoplasmic tail, was expressed in MDCK and LLC-PK1 cells. This protein was restricted to the basolateral membrane in MDCK cells, but was localized to the apical membrane in LLC-PK1 cells. Similarly, HA- Y543, a construct in which a tyrosine-based motif was introduced into the cytoplasmic tail of influenza hemagglutinin, was sorted to the basolateral membrane of MDCK cells and retained at the apical membrane of LLC-PK1 cells. A chimera in which the cytoplasmic tail of the H,K-ATPase β subunit protein was replaced with the analogous region of the Na,K-ATPase β subunit polypeptide was localized to both surface domains of MDCK cells. Mutation of tyrosine-20 of the H,K-ATPase β subunit cytoplasmic sequence to an alanine was SUfficient to disrupt basolateral localization of this polypeptide. In contrast, these constructs all remain localized to the apical membrane in LLC-PK1 cells. The FcRII-B2 protein bears a di-leucine motif and is found at the basolateral membrane of both MDCK and LLC-PK1 cells. These results demonstrate that polarized epithelia are able to discriminate between different classes of specifically defined membrane protein sorting signals.
AB - Tyrosine-dependent sequence motifs are implicated in sorting membrane proteins to the basolateral domain of Madin-Darby canine kidney (MDCK) cells. We find that these motifs are interpreted differentially in various polarized epithelial cell types. The H,K-ATPase β subunit, which contains a tyrosine- based motif in its cytoplasmic tail, was expressed in MDCK and LLC-PK1 cells. This protein was restricted to the basolateral membrane in MDCK cells, but was localized to the apical membrane in LLC-PK1 cells. Similarly, HA- Y543, a construct in which a tyrosine-based motif was introduced into the cytoplasmic tail of influenza hemagglutinin, was sorted to the basolateral membrane of MDCK cells and retained at the apical membrane of LLC-PK1 cells. A chimera in which the cytoplasmic tail of the H,K-ATPase β subunit protein was replaced with the analogous region of the Na,K-ATPase β subunit polypeptide was localized to both surface domains of MDCK cells. Mutation of tyrosine-20 of the H,K-ATPase β subunit cytoplasmic sequence to an alanine was SUfficient to disrupt basolateral localization of this polypeptide. In contrast, these constructs all remain localized to the apical membrane in LLC-PK1 cells. The FcRII-B2 protein bears a di-leucine motif and is found at the basolateral membrane of both MDCK and LLC-PK1 cells. These results demonstrate that polarized epithelia are able to discriminate between different classes of specifically defined membrane protein sorting signals.
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U2 - 10.1074/jbc.273.41.26862
DO - 10.1074/jbc.273.41.26862
M3 - Article
C2 - 9756932
AN - SCOPUS:0032500602
SN - 0021-9258
VL - 273
SP - 26862
EP - 26869
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 41
ER -