The growth-regulatory protein HCRP1/hVps37A is a subunit of mammalian ESCRT-I and mediates receptor down-regulation

Kristi G Bache; Thomas Slagsvold; Alicia Cabezas; Ken R Rosendal; Camilla Raiborg; Harald Stenmark

doi:10.1091/mbc.e04-03-0250

The growth-regulatory protein HCRP1/hVps37A is a subunit of mammalian ESCRT-I and mediates receptor down-regulation

Mol Biol Cell. 2004 Sep;15(9):4337-46. doi: 10.1091/mbc.e04-03-0250. Epub 2004 Jul 7.

Authors

Kristi G Bache¹, Thomas Slagsvold, Alicia Cabezas, Ken R Rosendal, Camilla Raiborg, Harald Stenmark

Affiliation

¹ Department of Biochemistry, The Norwegian Radium Hospital, Montebello, N-0310 Oslo, Norway.

Abstract

The biogenesis of multivesicular bodies and endosomal sorting of membrane cargo are driven forward by the endosomal sorting complexes required for transport, ESCRT-I, -II, and -III. ESCRT-I is characterized in yeast as a complex consisting of Vps23, Vps28, and Vps37. Whereas mammalian homologues of Vps23 and Vps28 (named Tsg101 and hVps28, respectively) have been identified and characterized, a mammalian counterpart of Vps37 has not yet been identified. Here, we show that a regulator of proliferation, hepatocellular carcinoma related protein 1 (HCRP1), interacts with Tsg101, hVps28, and their upstream regulator Hrs. The ability of HCRP1 (which we assign the alternative name hVps37A) to interact with Tsg101 is conferred by its mod(r) domain and is shared with hVps37B and hVps37C, two other mod(r) domain-containing proteins. HCRP1 cofractionates with Tsg101 and hVps28 by size exclusion chromatography and colocalizes with hVps28 on LAMP1-positive endosomes. Whereas depletion of Tsg101 by siRNA reduces cellular levels of both hVps28 and HCRP1, depletion of HCRP1 has no effect on Tsg101 or hVps28. Nevertheless, HCRP1 depletion strongly retards epidermal growth factor (EGF) receptor degradation. Together, these results indicate that HCRP1 is a subunit of mammalian ESCRT-I and that its function is essential for lysosomal sorting of EGF receptors.

Publication types

Comparative Study
Research Support, Non-U.S. Gov't

MeSH terms

Amino Acid Sequence
DNA-Binding Proteins / genetics
DNA-Binding Proteins / metabolism
Down-Regulation
Endosomal Sorting Complexes Required for Transport
Endosomes / metabolism
ErbB Receptors / metabolism*
GTPase-Activating Proteins / metabolism
HeLa Cells
Humans
Lysosomal Membrane Proteins
Lysosomes / metabolism
Membrane Glycoproteins / metabolism
Molecular Sequence Data
Phosphoproteins / metabolism
Protein Subunits
RNA, Small Interfering / genetics
Saccharomyces cerevisiae / genetics
Saccharomyces cerevisiae Proteins / genetics
Sequence Homology, Amino Acid
Species Specificity
Transcription Factors / genetics
Transcription Factors / metabolism
Two-Hybrid System Techniques
Vesicular Transport Proteins / chemistry*
Vesicular Transport Proteins / genetics
Vesicular Transport Proteins / metabolism*

Substances

DNA-Binding Proteins
Endosomal Sorting Complexes Required for Transport
GTPase-Activating Proteins
LAMP1 protein, human
Lysosomal Membrane Proteins
Membrane Glycoproteins
Phosphoproteins
Protein Subunits
RNA, Small Interfering
SRN2 protein, S cerevisiae
Saccharomyces cerevisiae Proteins
Transcription Factors
Tsg101 protein
VPS28 protein, human
VPS37A protein, human
Vesicular Transport Proteins
hepatocyte growth factor-regulated tyrosine kinase substrate
ErbB Receptors