Dissecting interactions between EB1, microtubules and APC in cortical clusters at the plasma membrane

2002 ◽  
Vol 115 (8) ◽  
pp. 1583-1590 ◽  
Author(s):  
Angela I. M. Barth ◽  
Kathleen A. Siemers ◽  
W. James Nelson
Keyword(s):  
Amino Acids ◽  
Cluster Formation ◽  
Adenomatous Polyposis ◽  
Polyposis Coli ◽  
Binding Domains ◽  
C Terminus ◽  
Endogenous Proteins ◽  
Apc Protein ◽  
Necessary And Sufficient ◽  
Armadillo Repeats

End-binding protein (EB) 1 binds to the C-terminus of adenomatous polyposis coli (APC) protein and to the plus ends of microtubules (MT) and has been implicated in the regulation of APC accumulation in cortical clusters at the tip of extending membranes. We investigated which APC domains are involved in cluster localization and whether binding to EB1 or MTs is essential for APC cluster localization. Armadillo repeats of APC that lack EB1- and MT-binding domains are necessary and sufficient for APC localization in cortical clusters; an APC fragment lacking the armadillo repeats, but containing MT-and EB1-binding domains, does not localize to the cortical clusters but instead co-aligns with MTs throughout the cell. Significantly, analysis of endogenous proteins reveals that EB1 does not accumulate in the APC clusters. However, overexpressed EB1 does accumulate in APC clusters; the APC-binding domain in EB1 is located in the C-terminal region of EB1 between amino acids 134 and 268. Overexpressed APC- or MT-binding domains of EB1 localize to APC cortical clusters and MT, respectively, without affecting APC cluster formation itself. These results show that localization of APC in cortical clusters is different from that of EB1 at MT plus ends and appears to be independent of EB1.

scholarly journals Sir3p Domains Involved in the Initiation of Telomeric Silencing in Saccharomyces cerevisiae

Genetics ◽  
1998 ◽  
Vol 150 (3) ◽  
pp. 977-986 ◽  
Author(s):  
Yangsuk Park ◽  
John Hanish ◽  
Arthur J Lustig
Keyword(s):  
Amino Acids ◽  
Active Site ◽  
Fusion Proteins ◽  
Initiation Site ◽  
Negative Control ◽  
Model System ◽  
Mutant Protein ◽  
Regulatory Domain ◽  
C Terminus ◽  
Necessary And Sufficient

Abstract Previous studies from our laboratory have demonstrated that tethering of Sir3p at the subtelomeric/telomeric junction restores silencing in strains containing Rap1-17p, a mutant protein unable to recruit Sir3p. This tethered silencing assay serves as a model system for the early events that follow recruitment of silencing factors, a process we term initiation. A series of LexA fusion proteins in-frame with various Sir3p fragments were constructed and tested for their ability to support tethered silencing. Interestingly, a region comprising only the C-terminal 144 amino acids, termed the C-terminal domain (CTD), is both necessary and sufficient for restoration of silencing. Curiously, the LexA-Sir3N205 mutant protein overcomes the requirement for the CTD, possibly by unmasking a cryptic initiation site. A second domain spanning amino acids 481-835, termed the nonessential for initiation domain (NID), is dispensable for the Sir3p function in initiation, but is required for the recruitment of the Sir4p C terminus. In addition, in the absence of the N-terminal 481 amino acids, the NID negatively influences CTD activity. This suggests the presence of a third region, consisting of the N-terminal half (1-481) of Sir3p, termed the positive regulatory domain (PRD), which is required to initiate silencing in the presence of the NID. These data suggest that the CTD “active” site is under both positive and negative control mediated by multiple Sir3p domains.

scholarly journals The Adenomatous Polyposis Coli Protein Is Required for the Formation of Robust Spindles Formed in CSF Xenopus Extracts

2004 ◽  
Vol 15 (6) ◽  
pp. 2978-2991 ◽  
Author(s):  
Dina Dikovskaya ◽  
Ian P. Newton ◽  
Inke S. Näthke
Keyword(s):  
Adenomatous Polyposis Coli ◽  
Chromosomal Instability ◽  
Adenomatous Polyposis ◽  
Mitotic Spindles ◽  
Polyposis Coli ◽  
Adenomatous Polyposis Coli Protein ◽  
Microtubule Binding ◽  
Microtubule Polymerization ◽  
Large N ◽  
Apc Protein

Mutations in the adenomatous polyposis coli (APC) protein occur early in colon cancer and correlate with chromosomal instability. Here, we show that depletion of APC from cystostatic factor (CSF) Xenopus extracts leads to a decrease in microtubule density and changes in tubulin distribution in spindles and asters formed in such extracts. Addition of full-length APC protein or a large, N-terminally truncated APC fragment to APC-depleted extracts restored normal spindle morphology and the intact microtubule-binding site of APC was necessary for this rescue. These data indicate that the APC protein plays a role in the formation of spindles that is dependent on its effect on microtubules. Spindles formed in cycled extracts were not sensitive to APC depletion. In CSF extracts, spindles predominantly formed from aster-like intermediates, whereas in cycled extracts chromatin was the major site of initial microtubule polymerization. These data suggest that APC is important for centrosomally driven spindle formation, which was confirmed by our finding that APC depletion reduced the size of asters nucleated from isolated centrosomes. We propose that lack of microtubule binding in cancer-associated mutations of APC may contribute to defects in the assembly of mitotic spindles and lead to missegregation of chromosomes.

Evidence for the involvement of adenomatous polyposis coli (APC) protein in maintaining cellular distributions of α3β4 nicotinic receptors

2011 ◽  
Vol 489 (2) ◽  
pp. 105-109
Author(s):  
Tulaya Potaros ◽  
Srichan Phornchirasilp ◽  
Susan B. McKay ◽  
Tatiana F. González-Cestari ◽  
R. Thomas Boyd ◽  
...  
Keyword(s):  
Adenomatous Polyposis Coli ◽  
Nicotinic Receptors ◽  
Adenomatous Polyposis ◽  
Polyposis Coli ◽  
Apc Protein

scholarly journals Cdc42 and noncanonical Wnt signal transduction pathways cooperate to promote cell polarity

2007 ◽  
Vol 178 (3) ◽  
pp. 355-361 ◽  
Author(s):  
Karni Schlessinger ◽  
Edward J. McManus ◽  
Alan Hall
Keyword(s):  
Signal Transduction ◽  
Wnt Signaling Pathway ◽  
Signal Transduction Pathway ◽  
Leading Edge ◽  
Transduction Pathway ◽  
Adenomatous Polyposis ◽  
Polyposis Coli ◽  
Gsk 3Β ◽  
Apc Protein ◽  
Wnt Signal

Scratch-induced disruption of cultured monolayers induces polarity in front row cells that can be visualized by spatially localized polymerization of actin at the front of the cell and reorientation of the centrosome/Golgi to face the leading edge. We previously reported that centrosomal reorientation and microtubule polarization depend on a Cdc42-regulated signal transduction pathway involving activation of the Par6/aPKC complex followed by inhibition of GSK-3β and accumulation of the adenomatous polyposis coli (APC) protein at the plus ends of leading-edge microtubules. Using monolayers of primary rodent embryo fibroblasts, we show here that dishevelled (Dvl) and axin, two major components of the Wnt signaling pathway are required for centrosome reorientation and that Wnt5a is required for activation of this pathway. We conclude that disruption of cell–cell contacts leads to the activation of a noncanonical Wnt/dishevelled signal transduction pathway that cooperates with Cdc42/Par6/aPKC to promote polarized reorganization of the microtubule cytoskeleton.

scholarly journals APC binds intermediate filaments and is required for their reorganization during cell migration

2013 ◽  
Vol 200 (3) ◽  
pp. 249-258 ◽  
Author(s):  
Yasuhisa Sakamoto ◽  
Batiste Boëda ◽  
Sandrine Etienne-Manneville
Keyword(s):  
Cell Migration ◽  
Glial Fibrillary Acidic Protein ◽  
Intermediate Filaments ◽  
Carcinoma Cells ◽  
Adenomatous Polyposis ◽  
Polyposis Coli ◽  
Cellular Functions ◽  
Migration Assay ◽  
Armadillo Repeats

Intermediate filaments (IFs) are components of the cytoskeleton involved in most cellular functions, including cell migration. Primary astrocytes mainly express glial fibrillary acidic protein, vimentin, and nestin, which are essential for migration. In a wound-induced migration assay, IFs reorganized to form a polarized network that was coextensive with microtubules in cell protrusions. We found that the tumor suppressor adenomatous polyposis coli (APC) was required for microtubule interaction with IFs and for microtubule-dependent rearrangements of IFs during astrocyte migration. We also show that loss or truncation of APC correlated with the disorganization of the IF network in glioma and carcinoma cells. In migrating astrocytes, vimentin-associated APC colocalized with microtubules. APC directly bound polymerized vimentin via its armadillo repeats. This binding domain promoted vimentin polymerization in vitro and contributed to the elongation of IFs along microtubules. These results point to APC as a crucial regulator of IF organization and confirm its fundamental role in the coordinated regulation of cytoskeletons.

The C-terminal domain of the adenomatous polyposis coli (Apc) protein is involved in thyroid morphogenesis and function

2011 ◽  
Vol 44 (4) ◽  
pp. 207-212 ◽  
Author(s):  
Atsushi Yokoyama ◽  
Ryuji Nomura ◽  
Masafumi Kurosumi ◽  
Atsushi Shimomura ◽  
Takanori Onouchi ◽  
...  
Keyword(s):  
Adenomatous Polyposis Coli ◽  
Adenomatous Polyposis ◽  
Polyposis Coli ◽  
Terminal Domain ◽  
And Function ◽  
Apc Protein

Adenomatous Polyposis Coli (APC) Protein Expression in Primary and Metastatic Serous Ovarian Carcinoma

2002 ◽  
Vol 10 (3) ◽  
pp. 175-180 ◽  
Author(s):  
Eleonora Karbova ◽  
Ben Davidson ◽  
Krassimir Metodiev ◽  
Claes G. Tropé ◽  
Jahn M. Nesland
Keyword(s):  
Protein Expression ◽  
Ovarian Carcinoma ◽  
Adenomatous Polyposis Coli ◽  
Adenomatous Polyposis ◽  
Polyposis Coli ◽  
Serous Ovarian Carcinoma ◽  
Apc Protein
Sign in / Sign up

Export Citation Format

Share Document