SPC3/YLR066W Summary Help

Standard Name SPC3 1
Systematic Name YLR066W
Feature Type ORF, Verified
Description Subunit of signal peptidase complex; complex catalyzes cleavage of N-terminal signal sequences of proteins targeted to the secretory pathway; homologous to mammalian SPC22/23; other members of the complex are Spc1p, Spc2p, and Sec11p (1, 2 and see Summary Paragraph)
Name Description Signal Peptidase Complex 2
Chromosomal Location
ChrXII:267169 to 267723 | ORF Map | GBrowse
Gene Ontology Annotations All SPC3 GO evidence and references
  View Computational GO annotations for SPC3
Molecular Function
Manually curated
Biological Process
Manually curated
Cellular Component
Manually curated
Regulators 7 genes
Large-scale survey
reduction of function
18 total interaction(s) for 14 unique genes/features.
Physical Interactions
  • Affinity Capture-MS: 8
  • Affinity Capture-RNA: 2
  • PCA: 2

Genetic Interactions
  • Dosage Rescue: 1
  • Positive Genetic: 1
  • Synthetic Lethality: 4

Expression Summary
Length (a.a.) 184
Molecular Weight (Da) 21,349
Isoelectric Point (pI) 9.52
Phosphorylation PhosphoGRID | PhosphoPep Database
sequence information
ChrXII:267169 to 267723 | ORF Map | GBrowse
Last Update Coordinates: 2011-02-03 | Sequence: 1996-07-31
Subfeature details
Most Recent Updates
Coordinates Sequence
CDS 1..555 267169..267723 2011-02-03 1996-07-31
Retrieve sequences
Analyze Sequence
S288C only
S288C vs. other species
S288C vs. other strains
External Links All Associated Seq | Entrez Gene | Entrez RefSeq Protein | MIPS | Search all NCBI (Entrez) | UniProtKB
Primary SGDIDS000004056

SPC3 encodes a subunit of the signal peptidase complex (SPC), which cleaves the signal sequence from proteins targeted to the endoplasmic reticulum (ER) (1, 2). Signal peptide cleavage occurs concomitantly with translocation through the translocon pore into the ER. In yeast, translocation can occur cotranslationally or posttranslationally, whereas in mammals translocation is always cotranslational. The process of protein translocation into the ER is reviewed in references 3 and 4.

The yeast SPC comprises four proteins, Spc1p, Spc2p, Spc3p, and Sec11p (5, 6). Spc3p is homologous to the mammalian signal peptidase subunit SPC22/23 (1, 2). SPC3 is essential for viability and for signal peptidase activity (1, 2). Depletion of Spc3p causes loss of signal peptidase activity and reduces levels of the other SPC proteins (2). Overexpression of SPC3 suppresses a temperature-sensitive mutation in SEC11, which encodes the catalytic SPC subunit (1), and Spc3p and Sec11p can be coimmunoprecipitated (7).

Last updated: 2000-12-08 Contact SGD

References cited on this page View Complete Literature Guide for SPC3
1) Fang H, et al.  (1997) In addition to SEC11, a newly identified gene, SPC3, is essential for signal peptidase activity in the yeast endoplasmic reticulum. J Biol Chem 272(20):13152-8
2) Meyer HA and Hartmann E  (1997) The yeast SPC22/23 homolog Spc3p is essential for signal peptidase activity. J Biol Chem 272(20):13159-64
3) Rapoport TA, et al.  (1996) Protein transport across the eukaryotic endoplasmic reticulum and bacterial inner membranes. Annu Rev Biochem 65:271-303
4) Johnson AE and van Waes MA  (1999) The translocon: a dynamic gateway at the ER membrane. Annu Rev Cell Dev Biol 15:799-842
5) YaDeau JT, et al.  (1991) Yeast signal peptidase contains a glycoprotein and the Sec11 gene product. Proc Natl Acad Sci U S A 88(2):517-21
6) Antonin W, et al.  (2000) Interactions between Spc2p and other components of the endoplasmic reticulum translocation sites of the yeast Saccharomyces cerevisiae. J Biol Chem 275(44):34068-72
7) VanValkenburgh C, et al.  (1999) The catalytic mechanism of endoplasmic reticulum signal peptidase appears to be distinct from most eubacterial signal peptidases. J Biol Chem 274(17):11519-25