Abstract
Clathrin is a major coat protein involved in sorting and retention of proteins at the late Golgi and in endocytosis from the cell surface. The clathrin triskelion contains three heavy chains, which provide the structural backbone of the clathrin lattice and three light chains, which are thought to regulate the formation or disassembly of clathrin coats. To better understand the function of the clathrin light chain, we characterized yeast strains carrying a disruption of the clathrin light chain gene (CLC1). Light chain-deficient cells showed phenotypes similar to those displayed by yeast that have a disruption in the clathrin heavy chain gene (CHC1). In clc1-Δ cells, the steady state level of the clathrin heavy chain was reduced to 20%-25% of wild-type levels and most of the heavy chain was not trimerized. If CHC1 was overexpressed in clc1-Δ cells, heavy chain trimers were detected and several clc1-Δ phenotypes were partially rescued. These results indicate that the light chain is important for heavy chain trimerization and the heavy chain still has some function in the absence of the light chain. In yeast, deletion of CHC1 is lethal in strains carrying the scd1-i allele, while strains carrying the scd1-v allele can survive without the heavy chain. In previous studies we isolated several multicopy suppressors of inviability of chc1-Δ scd1-i cells. Surprisingly, one of these suppressors, SCD4, is identical to CLC1. Overexpression of CLC1 in viable chc1-Δ scd1-v strains rescued some but not all of the phenotypes displayed by these cells. In the absence of the heavy chain, the light chain was not found in a high molecular mass complex, but still associated with membranes. These results suggest that the light chain can function independently of the clathrin heavy chain in yeast.
| Original language | English |
|---|---|
| Pages (from-to) | 899-910 |
| Number of pages | 12 |
| Journal | Journal of Cell Science |
| Volume | 110 |
| Issue number | 7 |
| State | Published - Apr 1 1997 |
| Externally published | Yes |
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Keywords
- Clathrin
- Endocytosis
- Golgi retention
- Saccharomyces cerevisiae
- Triskelion
ASJC Scopus subject areas
- Cell Biology
Cite this
Novel functions of clathrin light chains : Clathrin heavy chain trimerization is defective in light chain-deficient yeast. / Huang, Kristen M.; Gullberg, Lisa; Nelson, Karen K.; Stefan, Christopher J.; Blumer, Kendall; Lemmon, Sandra.
In: Journal of Cell Science, Vol. 110, No. 7, 01.04.1997, p. 899-910.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Novel functions of clathrin light chains
T2 - Clathrin heavy chain trimerization is defective in light chain-deficient yeast
AU - Huang, Kristen M.
AU - Gullberg, Lisa
AU - Nelson, Karen K.
AU - Stefan, Christopher J.
AU - Blumer, Kendall
AU - Lemmon, Sandra
PY - 1997/4/1
Y1 - 1997/4/1
N2 - Clathrin is a major coat protein involved in sorting and retention of proteins at the late Golgi and in endocytosis from the cell surface. The clathrin triskelion contains three heavy chains, which provide the structural backbone of the clathrin lattice and three light chains, which are thought to regulate the formation or disassembly of clathrin coats. To better understand the function of the clathrin light chain, we characterized yeast strains carrying a disruption of the clathrin light chain gene (CLC1). Light chain-deficient cells showed phenotypes similar to those displayed by yeast that have a disruption in the clathrin heavy chain gene (CHC1). In clc1-Δ cells, the steady state level of the clathrin heavy chain was reduced to 20%-25% of wild-type levels and most of the heavy chain was not trimerized. If CHC1 was overexpressed in clc1-Δ cells, heavy chain trimers were detected and several clc1-Δ phenotypes were partially rescued. These results indicate that the light chain is important for heavy chain trimerization and the heavy chain still has some function in the absence of the light chain. In yeast, deletion of CHC1 is lethal in strains carrying the scd1-i allele, while strains carrying the scd1-v allele can survive without the heavy chain. In previous studies we isolated several multicopy suppressors of inviability of chc1-Δ scd1-i cells. Surprisingly, one of these suppressors, SCD4, is identical to CLC1. Overexpression of CLC1 in viable chc1-Δ scd1-v strains rescued some but not all of the phenotypes displayed by these cells. In the absence of the heavy chain, the light chain was not found in a high molecular mass complex, but still associated with membranes. These results suggest that the light chain can function independently of the clathrin heavy chain in yeast.
AB - Clathrin is a major coat protein involved in sorting and retention of proteins at the late Golgi and in endocytosis from the cell surface. The clathrin triskelion contains three heavy chains, which provide the structural backbone of the clathrin lattice and three light chains, which are thought to regulate the formation or disassembly of clathrin coats. To better understand the function of the clathrin light chain, we characterized yeast strains carrying a disruption of the clathrin light chain gene (CLC1). Light chain-deficient cells showed phenotypes similar to those displayed by yeast that have a disruption in the clathrin heavy chain gene (CHC1). In clc1-Δ cells, the steady state level of the clathrin heavy chain was reduced to 20%-25% of wild-type levels and most of the heavy chain was not trimerized. If CHC1 was overexpressed in clc1-Δ cells, heavy chain trimers were detected and several clc1-Δ phenotypes were partially rescued. These results indicate that the light chain is important for heavy chain trimerization and the heavy chain still has some function in the absence of the light chain. In yeast, deletion of CHC1 is lethal in strains carrying the scd1-i allele, while strains carrying the scd1-v allele can survive without the heavy chain. In previous studies we isolated several multicopy suppressors of inviability of chc1-Δ scd1-i cells. Surprisingly, one of these suppressors, SCD4, is identical to CLC1. Overexpression of CLC1 in viable chc1-Δ scd1-v strains rescued some but not all of the phenotypes displayed by these cells. In the absence of the heavy chain, the light chain was not found in a high molecular mass complex, but still associated with membranes. These results suggest that the light chain can function independently of the clathrin heavy chain in yeast.
KW - Clathrin
KW - Endocytosis
KW - Golgi retention
KW - Saccharomyces cerevisiae
KW - Triskelion
UR - http://www.scopus.com/inward/record.url?scp=0030975677&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0030975677&partnerID=8YFLogxK
M3 - Article
C2 - 9133677
AN - SCOPUS:0030975677
VL - 110
SP - 899
EP - 910
JO - Journal of Cell Science
JF - Journal of Cell Science
SN - 0021-9533
IS - 7
ER -