Article

The interaction of two tethering factors, p115 and COG complex, is required for Golgi integrity.

Department of Cell Biology, Fukuoka University School of Medicine, Jonan-ku, Fukuoka 814-0180, Japan.
Traffic (impact factor: 4.92). 04/2007; 8(3):270-84. DOI:10.1111/j.1600-0854.2006.00530.x pp.270-84
Source: PubMed

ABSTRACT The vesicle-tethering protein p115 functions in endoplasmic reticulum-Golgi trafficking. We explored the function of homologous region 2 (HR2) of the p115 head domain that is highly homologous with the yeast counterpart, Uso1p. By expression of p115 mutants in p115 knockdown (KD) cells, we found that deletion of HR2 caused an irregular assembly of the Golgi, which consisted of a cluster of mini-stacked Golgi fragments, and gathered around microtubule-organizing center in a microtubule-dependent manner. Protein interaction analyses revealed that p115 HR2 interacted with Cog2, a subunit of the conserved oligomeric Golgi (COG) complex that is known another putative cis-Golgi vesicle-tethering factor. The interaction between p115 and Cog2 was found to be essential for Golgi ribbon reformation after the disruption of the ribbon by p115 KD or brefeldin A treatment and recovery by re-expression of p115 or drug wash out, respectively. The interaction occurred only in interphase cells and not in mitotic cells. These results strongly suggested that p115 plays an important role in the biogenesis and maintenance of the Golgi by interacting with the COG complex on the cis-Golgi in vesicular trafficking.

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Keywords

biogenesis
 
COG complex
 
deletion
 
drug wash
 
endoplasmic reticulum-Golgi trafficking
 
Golgi ribbon reformation
 
homologous region 2
 
interacting
 
irregular assembly
 
microtubule-organizing center
 
mitotic cells
 
p115 head domain
 
p115 HR2 interacted
 
p115 knockdown
 
Protein interaction analyses
 
putative cis-Golgi vesicle-tethering factor
 
subunit
 
Uso1p
 
vesicle-tethering protein p115 functions
 
yeast counterpart
 

Miwa Sohda