A class of membrane proteins with a C-terminal anchor.

Integral membrane proteins are generally targeted to translocation-competent membranes by virtue of signal sequences located close to the N-terminus of the polypeptide chain. Membrane anchoring is caused by the signal sequence or other hydrophobic segments located after it in the amino acid sequence. However, some integral membrane proteins do not follow these rules. The members of one class of nonconformist membrane proteins have no signal sequence, but instead possess a hydrophobic segment near the C-terminus that orients them with their N-termini in the cytoplasm. Members of this class are found in many organelles and are probably inserted into membranes by an unusual mechanism.

[1]  H. Khorana,et al.  The membrane-embedded segment of cytochrome b5 as studied by cross-linking with photoactivatable phospholipids. II. The nontransferable form. , 1983, The Journal of biological chemistry.

[2]  T. Rapoport,et al.  Direct probing of the interaction between the signal sequence of nascent preprolactin and the signal recognition particle by specific cross-linking , 1987, The Journal of cell biology.

[3]  N. Borgese,et al.  Both the outer mitochondrial membrane and the microsomal forms of cytochrome b5 reductase contain covalently bound myristic acid. Quantitative analysis on the polyvinylidene difluoride-immobilized proteins. , 1990, The Biochemical journal.

[4]  M. Cleary,et al.  Membrane topology of the Bcl-2 proto-oncogenic protein demonstrated in vitro. , 1990, The Journal of biological chemistry.

[5]  P. Strittmatter,et al.  The nonpolar peptide segment of cytochrome b5. Binding to phospholipid vesicles and identification of the fluorescent tryptophanyl residue. , 1978, The Journal of biological chemistry.

[6]  D. Verma,et al.  Synthesis of rat liver microsomal cytochrome b5 by free ribosomes , 1980, The Journal of cell biology.

[7]  R. McCauley,et al.  Ubiquitin is involved in the in vitro insertion of monoamine oxidase B into mitochondrial outer membranes. , 1989, The Journal of biological chemistry.

[8]  T. Rapoport,et al.  Different modes of membrane interactions of the signal sequence of carp preproinsulin and of the insertion sequence of rabbit cytochrome b5. , 1982, European journal of biochemistry.

[9]  D. Andrews,et al.  Evidence for a two-step mechanism involved in assembly of functional signal recognition particle receptor , 1989, The Journal of cell biology.

[10]  P. Strittmatter,et al.  Structural and functional properties of the membrane binding segment of cytochrome b5. , 1978, The Journal of biological chemistry.

[11]  P. Strittmatter,et al.  Topography of the C terminus of cytochrome b5 tightly bound to dimyristoylphosphatidylcholine vesicles. , 1987, The Journal of biological chemistry.

[12]  V. L. Rath,et al.  The signal recognition particle receptor is a complex that contains two distinct polypeptide chains , 1986, The Journal of cell biology.

[13]  W. Neupert,et al.  The mitochondrial protein import apparatus. , 1990, Annual review of biochemistry.

[14]  A. Ito,et al.  Mitochondrial targeting signal of rat liver monoamine oxidase B is located at its carboxy terminus. , 1992, Journal of biochemistry.

[15]  A. Ito,et al.  The carboxy‐terminal 10 amino acid residues of cytochrome b5 are necessary for its targeting to the endoplasmic reticulum. , 1992, The EMBO journal.

[16]  G. Blobel,et al.  Translocation of proteins across the endoplasmic reticulum III. Signal recognition protein (SRP) causes signal sequence-dependent and site- specific arrest of chain elongation that is released by microsomal membranes , 1981, The Journal of cell biology.

[17]  T. Rapoport.  Transport of proteins across the endoplasmic reticulum membrane. , 1992, Science.

[18]  F. Benfenati,et al.  Tetanus and botulinum-B neurotoxins block neurotransmitter release by proteolytic cleavage of synaptobrevin , 1992, Nature.

[19]  B. Neel,et al.  The nontransmembrane tyrosine phosphatase PTP-1B localizes to the endoplasmic reticulum via its 35 amino acid C-terminal sequence , 1992, Cell.

[20]  D. Gallwitz,et al.  Identification and structure of four yeast genes (SLY) that are able to suppress the functional loss of YPT1, a member of the RAS superfamily , 1991, Molecular and cellular biology.

[21]  S. Ferro-Novick,et al.  Bos1p, a membrane protein required for ER to Golgi transport in yeast, co‐purifies with the carrier vesicles and with Bet1p and the ER membrane. , 1992, The EMBO journal.

[22]  D. Meyer,et al.  The human docking protein does not associate with the membrane of the rough endoplasmic reticulum via a signal or insertion sequence-mediated mechanism. , 1988, Biochemical and biophysical research communications.

[23]  P. Dupree,et al.  VIP21, a 21-kD membrane protein is an integral component of trans-Golgi- network-derived transport vesicles , 1992, The Journal of cell biology.

[24]  P. Strittmatter,et al.  The binding of cytochrome b 5 to liver microsomes. , 1972, The Journal of biological chemistry.

[25]  B. Oostra,et al.  In vitro mutagenesis of the putative membrane-binding domain of polyomavirus middle-T antigen , 1986, Journal of virology.

[26]  J. Ozols.  Structure of cytochrome b5 and its topology in the microsomal membrane. , 1989, Biochimica et biophysica acta.

[27]  S. Ferro-Novick,et al.  BET1, BOS1, and SEC22 are members of a group of interacting yeast genes required for transport from the endoplasmic reticulum to the Golgi complex , 1990, Molecular and cellular biology.