Alternative translation and retrotranslocation of cytosolic C3 that detects cytoinvasive bacteria
Kremlitzka, Mariann LU ; Colineau, Lucie LU ; Nowacka, Alicja A. LU ; Mohlin, Frida C. LU ; Wozniak, Katarzyna LU ; Blom, Anna M. LU
and King, Ben C.
LU
(2022)
In Cellular and Molecular Life Sciences
79(6).
- Abstract
Complement C3 was originally regarded as a serum effector protein, although recent data has emerged suggesting that intracellular C3 can also regulate basic cellular processes. Despite the growing interest in intracellular C3 functions, the mechanism behind its generation has not been demonstrated. In this study we show that C3 can be expressed from an alternative translational start site, resulting in C3 lacking the signal peptide, which is therefore translated in the cytosol. In contrast to the secreted form, alternatively translated cytosolic C3 is not glycosylated, is present mainly in a reduced state, and is turned over by the ubiquitin–proteasome system. C3 can also be retrotranslocated from the endoplasmic reticulum into the... (More)
Complement C3 was originally regarded as a serum effector protein, although recent data has emerged suggesting that intracellular C3 can also regulate basic cellular processes. Despite the growing interest in intracellular C3 functions, the mechanism behind its generation has not been demonstrated. In this study we show that C3 can be expressed from an alternative translational start site, resulting in C3 lacking the signal peptide, which is therefore translated in the cytosol. In contrast to the secreted form, alternatively translated cytosolic C3 is not glycosylated, is present mainly in a reduced state, and is turned over by the ubiquitin–proteasome system. C3 can also be retrotranslocated from the endoplasmic reticulum into the cytosol, structurally resembling secreted C3. Finally, we demonstrate that intracellular cytosolic C3 can opsonize invasive Staphylococcus aureus within epithelial cell, slowing vacuolar escape as well as impacting bacterial survival on subsequent exposure to phagocytes. Our work therefore reveals the existence and origin of intracellular, cytosolic C3, and demonstrates functions for cytosolic C3 in intracellular detection of cytoinvasive pathogens.
(Less)
- author
- Kremlitzka, Mariann
LU
; Colineau, Lucie
LU
; Nowacka, Alicja A.
LU
; Mohlin, Frida C.
LU
; Wozniak, Katarzyna
LU
; Blom, Anna M.
LU
and King, Ben C.
LU
- organization
- publishing date
- 2022-06
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Cellular trafficking, Complement factor C3, Intracellular complement, Pathogen sensing
- in
- Cellular and Molecular Life Sciences
- volume
- 79
- issue
- 6
- article number
- 291
- publisher
- Birkhäuser Verlag
- external identifiers
-
- scopus:85130638170
- pmid:35546365
- ISSN
- 1420-682X
- DOI
- 10.1007/s00018-022-04308-z
- language
- English
- LU publication?
- yes
- id
- 95212bc9-c689-4edb-aa08-2a1d89ce0886
- date added to LUP
- 2022-12-27 15:19:28
- date last changed
- 2024-04-18 19:12:54
@article{95212bc9-c689-4edb-aa08-2a1d89ce0886,
abstract = {{<p>Complement C3 was originally regarded as a serum effector protein, although recent data has emerged suggesting that intracellular C3 can also regulate basic cellular processes. Despite the growing interest in intracellular C3 functions, the mechanism behind its generation has not been demonstrated. In this study we show that C3 can be expressed from an alternative translational start site, resulting in C3 lacking the signal peptide, which is therefore translated in the cytosol. In contrast to the secreted form, alternatively translated cytosolic C3 is not glycosylated, is present mainly in a reduced state, and is turned over by the ubiquitin–proteasome system. C3 can also be retrotranslocated from the endoplasmic reticulum into the cytosol, structurally resembling secreted C3. Finally, we demonstrate that intracellular cytosolic C3 can opsonize invasive Staphylococcus aureus within epithelial cell, slowing vacuolar escape as well as impacting bacterial survival on subsequent exposure to phagocytes. Our work therefore reveals the existence and origin of intracellular, cytosolic C3, and demonstrates functions for cytosolic C3 in intracellular detection of cytoinvasive pathogens.</p>}},
author = {{Kremlitzka, Mariann and Colineau, Lucie and Nowacka, Alicja A. and Mohlin, Frida C. and Wozniak, Katarzyna and Blom, Anna M. and King, Ben C.}},
issn = {{1420-682X}},
keywords = {{Cellular trafficking; Complement factor C3; Intracellular complement; Pathogen sensing}},
language = {{eng}},
number = {{6}},
publisher = {{Birkhäuser Verlag}},
series = {{Cellular and Molecular Life Sciences}},
title = {{Alternative translation and retrotranslocation of cytosolic C3 that detects cytoinvasive bacteria}},
url = {{http://dx.doi.org/10.1007/s00018-022-04308-z}},
doi = {{10.1007/s00018-022-04308-z}},
volume = {{79}},
year = {{2022}},
}