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Title: Biotin Attachment Domain-Containing Proteins Irreversibly Inhibit Acetyl CoA Carboxylase

The first committed step in fatty acid synthesis is mediated by Acetyl-CoA carboxylase (ACCase), a biotin-dependent enzyme that carboxylates acetyl-CoA to produce malonyl-CoA. ACCase can be feedback-regulated by short-term (reversible) and longer-term (irreversible) inhibition upon oversupply of fatty acids (FA) provided by Tween80 (predominantly containing oleic acid; 18:1). Biotin-Attachment-Domain-Containing (BADC) proteins are inactive analogs of biotin carboxyl transfer protein (BCCP) that lack biotin and their incorporation into ACCase downregulates it by displacing active (biotin-containing) BCCP subunits. Individual T-DNA insertion lines of BADC1, BADC2, and BADC3 were used to generate badc1badc2 and badc1badc3. The badc1badc3 mutant and wild-type exhibited normal growth and development, however ACCase activity was 26% higher in badc1badc3 relative to wild-type and its seeds contained 30.1 %DW more FA and 32.6 %DW more TAG than wild-type. Cell suspension cultures were generated from leaves of badc1badc3 and wild-type plants to test whether BADC contributes to the irreversible phase of ACCase inhibition resulting from culture in medium containing 10mM Tween80. While the reversible phase of ACCase inhibition after two days of Tween80 feeding was equivalent for badc1badc3 and wild-type, the irreversible phase of inhibition following four days of Tween80 feeding was reduced by 50% in badc1badc3 relative to wild-type. Inmore » this work we present evidence for two important homeostatic roles for BADC proteins in downregulating ACCase activity: during normal growth and development, and by contributing to its long-term irreversible feedback inhibition resulting from oversupply of fatty acids.« less
Authors:
 [1] ;  [1] ;  [1] ;  [1]
  1. Brookhaven National Lab. (BNL), Upton, NY (United States). Biology Department
Publication Date:
Report Number(s):
BNL-203572-2018-JAAM
Journal ID: ISSN 0032-0889
Grant/Contract Number:
SC0012704
Type:
Accepted Manuscript
Journal Name:
Plant Physiology (Bethesda)
Additional Journal Information:
Journal Name: Plant Physiology (Bethesda); Journal ID: ISSN 0032-0889
Publisher:
American Society of Plant Biologists
Research Org:
Brookhaven National Laboratory (BNL), Upton, NY (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22). Chemical Sciences, Geosciences & Biosciences Division; USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
Language:
English
Subject:
59 BASIC BIOLOGICAL SCIENCES
OSTI Identifier:
1435159
Alternate Identifier(s):
OSTI ID: 1432126