Localization and topology of ratp28, a member of a novel family of putative steroid-binding proteins.
We have cloned ratp28, a membrane protein from rat liver homologous to the previously described hpr6.6, a putative steroid-binding protein in humans. Ratp28 has a type II topology as determined by protease digestion experiments on intact and detergent-solubilized membranes. Subcellular fractionation by sucrose density centrifugation revealed a distribution for ratp28 identical to Bip as a marker for membranes of the endoplasmic reticulum. In these experiments no association was found with markers for Golgi or plasma membranes, indicating that ratp28 is localized to the endoplasmic reticulum.
Nölte
I
I
Biochemie-Zentrum, Heidelberg (BZH), University of Heidelberg, Im Neuenheimer Feld, 328, D-69120, Heidelberg, Germany.
Jeckel
D
D
Wieland
F T
FT
Sohn
K
K
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002352:Carrier Proteins / Q000032:analysis* / Q000737:chemistry / Q000235:genetics; D002458:Cell Fractionation; D003001:Cloning, Molecular; D003902:Detergents; D010450:Endopeptidases; D004721:Endoplasmic Reticulum / Q000378:metabolism; D015723:Gene Library; D007425:Intracellular Membranes / Q000378:metabolism; D008099:Liver / Q000378:metabolism* / Q000648:ultrastructure; D037601:Mannose-Binding Lectin / Q000031:analogs & derivatives*; D008565:Membrane Proteins / Q000032:analysis; D008969:Molecular Sequence Data; D051381:Rats; D011980:Receptors, Progesterone / Q000032:analysis; D011987:Receptors, Steroid / Q000032:analysis* / Q000737:chemistry / Q000235:genetics; D013552:Swine
D002352:Carrier Proteins; D003902:Detergents; D037601:Mannose-Binding Lectin; C445639:Mbl2 protein, mouse; D008565:Membrane Proteins; D011980:Receptors, Progesterone; D011987:Receptors, Steroid; D010450:Endopeptidases