Here , we show that a regulator of proliferation , hepatocellular carcinoma related protein 1 ( HCRP 1 ) , interacts with Tsg 101 , hVps 28 , and their upstream regulator Hrs . ^^^ The ability of HCRP 1 ( which we assign the alternative name hVps37A ) to interact with Tsg 101 is conferred by its mod ( r ) domain and is shared with hVps37B and hVps37C , two other mod ( r ) domain containing proteins . ^^^ HCRP 1 cofractionates with Tsg 101 and hVps 28 by size exclusion chromatography and colocalizes with hVps 28 on LAMP 1 positive endosomes . ^^^ Whereas depletion of Tsg 101 by siRNA reduces cellular levels of both hVps 28 and HCRP 1 , depletion of HCRP 1 has no effect on Tsg 101 or hVps 28 . ^^^ |