THESIS
2017
xiii, 49 pages : color illustrations ; 30 cm
Abstract
The Golgi apparatus is one of the microtubule organizing centers in mammalian cells that
regulate the noncentrosomal microtubule to plays essential roles in Golgi organization, Golgi
morphogenesis, polarized transport, cell motility, and cell differentiation. However, the control
mechanism of Golgi-derived microtubule remains indefinable. Recently, a proposed model
depicted that minus end of Golgi-derived microtubule is anchored and stabilized by a protein
complex composed by GM130, AKAP450, myomegalin, CAMSAP2 and CLASPs. Most of
these proteins are end binding proteins (EB) partners, GAS2L1 was identified as an new EB
partner by mass spectrometer. GAS2L1, a microtubule- and actin-binding protein, is involved
in regulating microtubule and actin dynamic as well as regulating the...[
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The Golgi apparatus is one of the microtubule organizing centers in mammalian cells that
regulate the noncentrosomal microtubule to plays essential roles in Golgi organization, Golgi
morphogenesis, polarized transport, cell motility, and cell differentiation. However, the control
mechanism of Golgi-derived microtubule remains indefinable. Recently, a proposed model
depicted that minus end of Golgi-derived microtubule is anchored and stabilized by a protein
complex composed by GM130, AKAP450, myomegalin, CAMSAP2 and CLASPs. Most of
these proteins are end binding proteins (EB) partners, GAS2L1 was identified as an new EB
partner by mass spectrometer. GAS2L1, a microtubule- and actin-binding protein, is involved
in regulating microtubule and actin dynamic as well as regulating the centrosome disjunction.
Beside its Centrosomal activity, I reveal that GAS2L1 is involved in the regulation of Golgi
reassembly and Golgi-derived microtubule growth. Using the CRISPR/CAS9 genome-editing
method, I established GAS2L1 knockout cell lines and studied the molecular mechanism of
Golgi assembly. Cells deficient of GAS2L1 showed defects in Golgi morphology and
nocodazole washout-induced reassembly. Furthermore, I found that Golgi-derived microtubule
regrowth after nocodazole washout was inhibited in the knockout cells. To reveal the detail
mechanism by which GAS2L1 regulates Golgi-derived microtubules, we screened for GAS2L-associated
proteins by a biochemical approach and identified CLASP1/2, which have known
functions in the regulation of Golgi-derived microtubules not only at minus end but also at
microtubule lattice and plus end. To conclude the findings, I suggest that GAS2L1 is important
for Golgi assembly and structural organization by forming functional complexes with CLASPs
to stabilize whole Golgi-derived microtubules.
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