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Dynamic regulation of lipid droplets in the microalgae Chlamydomonas reinhardtii
Author(s) -
TSAI CHIA-HONG,
Benning Christoph
Publication year - 2012
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.26.1_supplement.597.3
Subject(s) - chlamydomonas reinhardtii , perilipin , lipolysis , lipogenesis , chlamydomonas , lipid droplet , mutant , biochemistry , microbiology and biotechnology , biology , chemistry , lipid metabolism , gene , adipose tissue
Under nitrogen deprivation the microalgae Chlamydomonas reinhardtii stores triacylglycerols (TAGs) in the lipid droplets. Upon resupply with nitrogen, TAGs are metabolized to generate energy and membrane building blocks needed by the cell. To understand how the lipid droplets remain intact in the presence of lipases and to determine factors required for the transition from lipogenesis to lipolysis, antibodies against the most abundant perilipin‐type protein in the Chlamydomonas lipid droplet (MLDP) were produced. Using these antibodies we were able to demonstrate the phosphorylation of MLDP and the possible recruitment of different sets of proteins to lipid droplets during lipogenesis and lipolysis. We also applied an antibody‐based dot‐blot technique to screen for the mutants unable to hydrolyze TAGs during lipolysis. One of the compromised‐hydrolysis‐of‐TAG mutants, cht7 showed 10‐fold higher TAG levels than the wild type after the induction of lipolysis. In addition, cell growth of cht7 under this condition was strongly delayed. The mutant phenotype suggests a direct coupling of lipolysis with cell cycle progression. Likely candidate genes responsible for the phenotype in this mutant were identified. This research is sponsored by United States Air Force Office of Scientific Research.