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Tissue specific membrane association of α1T, a truncated form of the α1 subunit of the Na pump
Author(s) -
Alien Julius C.,
Pressley Thomas A.,
Odebunmi Timothy,
Medford Russell M.
Publication year - 1994
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(94)80210-6
Subject(s) - protein subunit , association (psychology) , chemistry , membrane , microbiology and biotechnology , biophysics , biology , biochemistry , psychology , gene , psychotherapist
We have assessed the Na pump α‐subunit isoform content utilizing site directed antibodies in two vascular smooth muscle (VSM) preparations known to contain functional Na pump sites, VSM microsomal fractions (Na + ,K + ‐ATPase) and intact primary confluent cells (ouabain inhibited 86 Rb uptake). A comparison of isoform content was made with kidney microsomes. Both VSM and kidney microsomes contained a full length α1 subunit (~100 kDa) as well as a truncated subunit, α1T (~66 kDa). SDS treatment of VSM microsomes effected an increase in Na + ,K + ‐ATPase and a retention of α1T. SDS treated kidney microsomes retained the α1 isoform and Na + ,K + ‐ATPase. Confluent VSM cells showed no detectable α1T, only α1T. In the absence of detectable full length α1, the α1T protein may represent a functional Na pump component in canine VSM.