Two splice variants of Golgi-microtubule-associated protein of 210 kDa (GMAP-210) differ in their binding to the cis-Golgi network.
Biochem J
; 357(Pt 3): 699-708, 2001 Aug 01.
Article
in En
| MEDLINE
| ID: mdl-11463340
ABSTRACT
GMAP-210 (Golgi-microtubule-associated protein of 210 kDa) is a peripheral Golgi protein that interacts with the minus end of microtubules through its C-terminus and with cis-Golgi network membranes through its N-terminus; it participates in the maintenance of the structural integrity of the Golgi apparatus [Infante, Ramos-Morales, Fedriani, Bornens and Rios (1999) J. Cell Biol. 145, 83--98]. We report here the cloning of a new isoform of GMAP-210 that lacks amino acid residues 105--196. On the basis of the analysis of the gmap-210 genomic sequence, we propose that the small isoform, GMAP-200, arises from alternative splicing of exon 4 of the primary transcript. Overexpression of GMAP-200 induces perturbations in both the Golgi apparatus and the microtubule network that are similar to those previously reported for GMAP-210 overexpression. We show that both isoforms are able to oligomerize under overexpression conditions. Analysis in vitro and in vivo, with the green fluorescent protein as a marker, reveals that the binding of the N-terminal domain of GMAP-200 to the cis-Golgi network membranes is lower than that of the N-terminal domain of GMAP-210. Implications for the regulation of interaction between the cis-Golgi network and microtubules are discussed.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Alternative Splicing
/
Golgi Apparatus
/
Microtubule-Associated Proteins
/
Microtubules
Type of study:
Risk_factors_studies
Limits:
Animals
/
Humans
Language:
En
Journal:
Biochem J
Year:
2001
Document type:
Article
Affiliation country:
Spain