Journal
JOURNAL OF BIOLOGICAL CHEMISTRY
Volume 285, Issue 34, Pages 26174-26181Publisher
AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC
DOI: 10.1074/jbc.M110.132548
Keywords
-
Categories
Funding
- Deutsche Forschungsgemeinschaft [596]
- Bundesministerium fur Bildung und Forschung (BMBF)
- Centre for Integrated Protein Science Munich
- Ludwig-Maximilians-University
Ask authors/readers for more resources
Nicastrin and its relative Nicalin (Nicastrin-like protein) are both members of larger protein complexes, namely gamma-secretase and the Nicalin-NOMO (Nodal modulator) complex. The gamma-secretase complex, which contains Presenilin, APH-1, and PEN-2 in addition to Nicastrin, catalyzes the proteolytic cleavage of the transmembrane domain of various proteins including the beta-amyloid precursor protein and Notch. Nicalin and its binding partner NOMO form a complex that was shown to modulate Nodal signaling in developing zebrafish embryos. Because its experimentally determined native size (200-220 kDa) could not be satisfyingly explained by the molecular masses of Nicalin (60 kDa) and NOMO(130 kDa), we searched in affinity-purified complex preparations for additional components in the low molecular mass range. A similar to 22-kDa protein was isolated and identified by mass spectrometry as transmembrane protein 147 (TMEM147), a novel, highly conserved membrane protein with a putative topology similar to APH-1. Like Nicalin and NOMO, it localizes to the endoplasmic reticulum and is expressed during early zebrafish development. Overexpression and knockdown experiments in cultured cells demonstrate a close relationship between the three proteins and suggest that they are components of the same complex. We present evidence that, similar to gamma-secretase, its assembly is hierarchical starting with the formation of a Nicalin-NOMO intermediate. Nicalin appears to represent the limiting factor regulating the assembly rate by stabilizing the other two components. We conclude that TMEM147 is a novel core component of the Nicalin-NOMO complex, further emphasizing its similarity with gamma-secretase.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available