A class of membrane proteins shaping the tubular endoplasmic reticulum.
How is the characteristic shape of a membrane bound organelle achieved? We have used an in vitro system to address the mechanism by which the tubular network of the endoplasmic reticulum (ER) is generated and maintained. Based on the inhibitory effect of sulfhydryl reagents and antibodies, network formation in vitro requires the integral membrane protein Rtn4a/NogoA, a member of the ubiquitous reticulon family. Both in yeast and mammalian cells, the reticulons are largely restricted to the tubular ER and are excluded from the continuous sheets of the nuclear envelope and peripheral ER. Upon overexpression, the reticulons form tubular membrane structures. The reticulons interact with DP1/Yop1p, a conserved integral membrane protein that also localizes to the tubular ER. These proteins share an unusual hairpin topology in the membrane. The simultaneous absence of the reticulons and Yop1p in S. cerevisiae results in disrupted tubular ER. We propose that these "morphogenic" proteins partition into and stabilize highly curved ER membrane tubules.
Howard Hughes Medical Institute and Department of Cell Biology, Harvard Medical School, 240 Longwood Avenue, Boston, MA 02115, USA.
Gia K
GK
Voeltz
William A
WA
Prinz
Yoko
Y
Shibata
Julia M
JM
Rist
Tom A
TA
Rapoport
D000818:Animals; D019556:COS Cells; D020013:Calcium Signaling; D002522:Chlorocebus aethiops; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D047908:Intracellular Signaling Peptides and Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D008565:Membrane Proteins / Q000737:chemistry / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D026901:Membrane Transport Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D009185:Myelin Proteins; D000070798:Nogo Proteins; D009865:Oocytes / Q000378:metabolism; D051381:Rats; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D014162:Transfection
D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D009185:Myelin Proteins; D000070798:Nogo Proteins; C000603199:RTN4 protein, human; D011994:Recombinant Proteins; C000603197:Rtn4 protein, rat; D029701:Saccharomyces cerevisiae Proteins; C426246:YOP1 protein, S cerevisiae