Reference: Blum R, et al. (1996) Tmp21 and p24A, two type I proteins enriched in pancreatic microsomal membranes, are members of a protein family involved in vesicular trafficking. J Biol Chem 271(29):17183-9

Reference Help

Abstract

We report here on the isolation, cloning, and expression of two Mr 21,000 proteins from rat pancreatic acinar cells, the rat-Tmp21 (transmembrane protein, Mr 21,000) and the rat-p24A. Both proteins are transmembrane proteins with type I topology and share weak but significant homology to one another (23% identity). We further show the cloning and characterization of the human homologs, hum-Tmp21, which is expressed in two variants (Tmp21-I and Tmp21-II), and hum-p24A. Tmp21 proteins and p24A have highly conserved COOH-terminal tails, which contain motifs related to the endoplasmic reticulum retention and retrieval consensus sequence KKXX. The rat-p24 sequence is identical to the hamster CHOp24, a recently characterized component of coatomer-coated transport vesicles, which defines a family of proteins (called the p24 family) proposed to be involved in vesicular transport processes (Stamnes, M. A., Craighead, M. W., Hoe, M. H., Lampen, N., Geromanos, S., Tempst, P., and Rothman, J. E.(1995) Proc. Natl. Acad. Sci. U. S. A. 92, 8011-8015). Sequence alignment and structural features identify the Tmp21 protein as a new member of this p24 family. Northern analysis of various tissues indicates that the Tmp21 proteins and the p24A protein are ubiquitously expressed. The integral membrane components Tmp21 and p24A are localized in microsomal membranes, zymogen granule membranes, and the plasma membrane and are absent from the cytosol. Both p24A and Tmp21 show weak homology to the yeast protein Emp24p, which recently has been shown to be involved in secretory protein transport from the endoplasmic reticulum to the Golgi apparatus. This leads us to conclude that the receptor-like Tmp21 and p24A are involved in vesicular targeting and protein transport.

Reference Type
Journal Article
Authors
Blum R, Feick P, Puype M, Vandekerckhove J, Klengel R, Nastainczyk W, Schulz I
Primary Lit For
Additional Lit For
Review For

Interaction Annotations

Increase the total number of rows showing on this page by using the pull-down located below the table, or use the page scroll at the table's top right to browse through the table's pages; use the arrows to the right of a column header to sort by that column; filter the table using the "Filter" box at the top of the table; click on the small "i" buttons located within a cell for an annotation to view further details about experiment type and any other genes involved in the interaction.

Interactor Interactor Type Assay Annotation Action Modification Phenotype Source Reference

Gene Ontology Annotations

Increase the total number of rows showing on this page using the pull-down located below the table, or use the page scroll at the table's top right to browse through the table's pages; use the arrows to the right of a column header to sort by that column; filter the table using the "Filter" box at the top of the table.

Gene Gene Ontology Term Qualifier Aspect Method Evidence Source Assigned On Annotation Extension Reference

Phenotype Annotations

Increase the total number of rows showing on this page using the pull-down located below the table, or use the page scroll at the table's top right to browse through the table's pages; use the arrows to the right of a column header to sort by that column; filter the table using the "Filter" box at the top of the table; click on the small "i" buttons located within a cell for an annotation to view further details.

Gene Phenotype Experiment Type Mutant Information Strain Background Chemical Details Reference

Regulation Annotations

Increase the total number of rows displayed on this page using the pull-down located below the table, or use the page scroll at the table's top right to browse through the table's pages; use the arrows to the right of a column header to sort by that column; to filter the table by a specific experiment type, type a keyword into the Filter box (for example, “microarray”); download this table as a .txt file using the Download button or click Analyze to further view and analyze the list of target genes using GO Term Finder, GO Slim Mapper, SPELL, or YeastMine.

Regulator Target Experiment Assay Construct Conditions Strain Background Reference