SEARCH · PubMed Health

Results for “Transmembrane protein 175”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources

PubMed1988

Transfer of functional EGF receptors to an IL3-dependent cell line.

Epidermal growth factor (EGF) is a small protein that acts as a mitogen for various epidermal, epithelial, and fibroblastic cells that bear specific EGF receptors. The molecule that binds EGF is a 175-kD transmembrane protein, with an extracellular ligand binding domain and an intracellular domain that possesses tyrosine kinase activity, thought to be involved in the mitogenic signalling process. Here we have constructed a recombinant murine retrovirus that transduces a human cDNA encoding the 175-kD protein and used this retrovirus to infect BAF3, a murine, bone marrow-derived cell line, which is dependent on the haematopoietic factor interleukin-3 (IL3) for its growth in culture. The EGF receptors expressed in the infected cells exhibit two affinity states, as well as EGF-stimulated autophosphorylation. Furthermore, EGF can replace IL3 in supporting short-term proliferation of these cells. These data identify functional properties of the EGF receptor upon expression of the 175-kD EGF binding protein in a haemotopoietic cell that does not express endogenous receptors. They also suggest that gene transfer of growth factor receptors to heterologous cells may allow novel growth stimuli to be exploited.

Animals↗

PubMed2026

A guide to selecting high-performing antibodies for TMEM175 (UniProt ID: Q9BSA9) for use in western blot, immunoprecipitation, and immunofluorescence.

TMEM175 is the pore-forming subunit of a lysosomal K+ channel complex that regulates lysosomal pH stability and membrane potential. To further investigate its cellular functions and implications in neurodegenerative diseases, antibody reagents are needed. Here we have characterized six TMEM175 commercial antibodies for western blot, immunoprecipitation, and immunofluorescence using a standardized experimental protocol based on comparing read-outs in knockout cell lines and isogenic parental controls. These studies are part of a larger, collaborative initiative seeking to address antibody reproducibility issues by characterizing commercially available antibodies for human proteins and publishing the results openly as a resource for the scientific community. While use of antibodies and protocols vary between laboratories, we encourage readers to use this report as a guide to select the most appropriate antibodies for their specific needs.

Humans↗

PubMed1991

Ligand-independent tyrosine phosphorylation of the receptor encoded by the c-neu oncogene.

Incubation of Swiss 3T3 murine fibroblasts at low temperatures induces phosphorylation on tyrosine of a transmembrane protein of 175 kDa. This phenomenon is time and temperature dependent and reaches a maximum after 2 hr at 4 degrees C. The 175 kDa protein phosphorylated in vivo at low temperatures can be immunoprecipitated by phosphotyrosine antibodies and displays auto-kinase activity in vitro in the presence of radiolabelled ATP. This molecule was found to react with anti-peptide antibodies directed against the product of the HER2/neu proto-oncogene only when immunoprecipitated with phosphotyrosine antibodies from cold-stimulated cells. Activation of protein kinase-C by treatment of the cells with phorbol esters, bombesin or PDGF inhibits the effect of the exposure to low temperatures. Phosphorylation of p175 is not induced by treatment of the cells with the phosphatases inhibitor sodium orthovanadate. These results suggest that, at low temperatures, the tyrosine kinase associated with the putative receptor encoded by c-neu is activated by physico-chemical modifications of the plasma membrane.

3T3 Cells↗

PubMed2006

HTPAP gene on chromosome 8p is a candidate metastasis suppressor for human hepatocellular carcinoma.

Our previous studies suggested that chromosome 8p deletion is associated with metastasis of hepatocellular carcinoma (HCC), in which some novel metastasis suppressor genes might be harbored. The present study aimed to identify the metastatic suppressor gene(s). A cDNA chip was constructed with the expressed sequence tags (ESTs) from chromosome 8p and used to compare the difference of expression profiling between the MHCC97-H and MHCC97-L cell lines with different metastatic potentials and similar genetic backgrounds. In all, 10 ESTs were significantly downregulated in MHCC97-H cell line with higher metastatic potential. One full-length gene, HTPAP (phosphatidic acid phosphatase type 2 domain containing 1B), was identified at chromosome 8p12. Sequencing and bioinformatic analyses revealed that HTPAP has 826 bp and encodes a putative protein of 175 amino acids with a transmembrane segment at the NH2 terminus, two protein kinase C phosphorylation site and one tyrosine kinase phosphorylation site. Its expression level in metastatic tumor tissues was much lower than that of primary HCC tissues. Both in vitro and in vivo assays suggested that HTPAP could suppress the invasion and metastasis of HCC. These suggested that HTPAP is a novel metastatic suppressor gene for HCC. The mechanism of the effect of HTPAP on HCC metastasis is not clear yet and deserves further investigation.

Amino Acid Sequence↗

PubMed2000

gdt1, a new signal transduction component for negative regulation of the growth-differentiation transition in Dictyostelium discoideum.

Discoidin I expression was used as a marker to screen for mutants affected in the growth-differentiation transition (GDT) of Dictyostelium. By REMI mutagenesis we have isolated mutant 2-9, an overexpressor of discoidin I. It displays normal morphogenesis but shows premature entry into the developmental cycle. The disrupted gene was denominated gdt1. The mutant phenotype was reconstructed by disruptions in different parts of the gene, suggesting that all had a complete loss of function. gdt1 was expressed in growing cells; the levels of protein and mRNA appear to increase with cell density and rapidly decrease with the onset of development. gdt1 encodes a 175-kDa protein with four putative transmembrane domains. In the C terminus, the derived amino acid sequence displays some similarity to the catalytic domain of protein kinases. Mixing experiments demonstrate that the gdt1(-) phenotype is cell autonomous. Prestarvation factor is secreted at wild-type levels. The response to folate, a negative regulator of discoidin expression, was not impaired in gdt1 mutants. Cells that lack the G protein alpha2 display a loss of discoidin expression and do not aggregate. gdt1(-)/Galpha2(-) double mutants show no aggregation but strong discoidin expression. This suggests that gdt1 is a negative regulator of the GDT downstream of or in a parallel pathway to Galpha2.

3' Untranslated Regions↗

PubMed1998

Fluconazole resistance associated with drug efflux and increased transcription of a drug transporter gene, PDH1, in Candida glabrata.

Sequential Candida glabrata isolates were obtained from the mouth of a patient infected with human immunodeficiency virus type 1 who was receiving high doses of fluconazole for oropharyngeal thrush. Fluconazole-susceptible colonies were replaced by resistant colonies that exhibited both increased fluconazole efflux and increased transcripts of a gene which codes for a protein with 72.5% identity to Pdr5p, an ABC multidrug transporter in Saccharomyces cerevisiae. The deduced protein had a molecular mass of 175 kDa and was composed of two homologous halves, each with six putative transmembrane domains and highly conserved sequences of ATP-binding domains. When the earliest and most azole-susceptible isolate of C. glabrata from this patient was exposed to fluconazole, increased transcripts of the PDR5 homolog appeared, linking azole exposure to regulation of this gene.

AIDS-Related Opportunistic Infections↗

PubMed2005

Proteomic analysis of mouse liver plasma membrane: use of differential extraction to enrich hydrophobic membrane proteins.

To comprehensively identify proteins of liver plasma membrane (PM), we isolated PMs from mouse liver by sucrose density gradient centrifugation. An optimized extraction method for whole PM proteins and several methods of differential extraction expected to enrich hydrophobic membrane proteins were tested. The extracted PM proteins were separated by 2-DE, and were identified by MALDI-TOF-MS, and ESI-quadrupole-TOF MS. As the complementary method, 1-DE-MS/MS was also used to identify PM proteins. The optimized lysis buffer containing urea, thiourea, CHAPS and NP-40 was able to extract more PM proteins, and treatment of PM samples with chloroform/methanol and sodium carbonate led to enrichment of more hydrophobic PM proteins. From the mouse liver PM fraction, 175 non-redundant gene products were identified, of which 88 (about 50%) were integral membrane proteins with one to seven transmembrane domains. The remaining products were probably membrane-associated and cytosolic proteins. The function distribution of all the identified liver PM proteins was analyzed; 40% represented enzymes, 12% receptors and 9% proteins with unknown function.

Animals↗

PubMed1999

A functional protein pore with a "retro" transmembrane domain.

Extended retro (reversed) peptide sequences have not previously been accommodated within functional proteins. Here, we show that the entire transmembrane portion of the beta-barrel of the pore-forming protein alpha-hemolysin can be formed by retrosequences comprising a total of 175 amino acid residues, 25 contributed by the central sequence of each subunit of the heptameric pore. The properties of wild-type and retro heptamers in planar bilayers are similar. The single-channel conductance of the retro pore is 15% less than that of the wild-type heptamer and its current-voltage relationship denotes close to ohmic behavior, while the wild-type pore is weakly rectifying. Both wild-type and retro pores are very weakly anion selective. These results and the examination of molecular models suggest that beta-barrels may be especially accepting of retro sequences compared to other protein folds. Indeed, the ability to form a retro domain could be diagnostic of a beta-barrel, explaining, for example, the activity of the retro forms of many membrane-permeabilizing peptides. By contrast with the wild-type subunits, monomeric retro subunits undergo premature assembly in the absence of membranes, most likely because the altered central sequence fails to interact with the remainder of the subunit, thereby initiating assembly. Despite this difficulty, a technique was devised for obtaining heteromeric pores containing both wild-type and retro subunits. Most probably as a consequence of unfavorable interstrand side-chain interactions, the heteromeric pores are less stable than either the wild-type or retro homoheptamers, as judged by the presence of subconductance states in single-channel recordings. Knowledge about the extraordinary plasticity of the transmembrane beta-barrel of alpha-hemolysin will be very useful in the de novo design of functional membrane proteins based on the beta-barrel motif.

Amino Acid Sequence↗

PubMed1999

Ligand binding sites on guinea pig C3aR: point and deletion mutations in the large extracellular loop and vicinity.

Human C3a receptor (huC3aR) belongs to the G-protein coupled receptor family chacterized by having seven transmembrane domains. The huC3aR is a unique member of this family having a large extracellular (EC) loop of 175 amino acids between the 4th and 5th transmembrane domains. Based on a comparison of C3aR sequences from several species, a number of charged and conserved amino acids (Asp182, Asp309, Asp310, and Arg331) in and near the large EC loop of guinea pig C3aR were replaced using site-directed mutagenesis. Competitive binding assays showed that changing Arg331 in guinea pig C3aR to Ala (or Gln), but not changing Asp182, Asp309, or Asp310 to Ala, resulted in complete loss of ligand binding activity. These results and major EC loop deletions demonstrated that an essential C3a binding site is present in the transmembrane portion of C3aR, but not in the large EC loop. Replacement of Arg331 by a noncharged residue was sufficient to eliminate ligand-receptor interactions.

Animals↗

PubMed2001

The major CD9 and CD81 molecular partner. Identification and characterization of the complexes.

By associating with specific partner molecules and with each other, the tetraspanins are thought to assemble multimolecular complexes that may be especially relevant with respect to metastasis. We have previously identified a 135-kDa molecule (CD9P-1) as a major molecular partner of CD9 in cancer cell lines. This molecule was identified, after immunoaffinity purification and mass spectrometry analysis, as the protein encoded by the KIAA1436 gene and the human ortholog of a rat protein known as FPRP. Cross-linking experiments detected a complex of the size of CD9 plus CD9P-1, showing that these glycoproteins directly associate with each other, probably in the absence of any other molecule. The use of chimeric CD9/CD82 molecules revealed the role of the second half of CD9, comprising the large extracellular loop and the fourth transmembrane domain. CD9P-1 was also shown to form separate complexes with CD81 and with an unidentified 175-kDa molecule. It also associated with other tetraspanins under conditions maintaining tetraspanin/tetraspanin interactions. The identification of a protein strongly linked to the tetraspanin web and the production of a specific monoclonal antibody will help to further characterize the role of this "web" under physiological and pathological conditions.

Animals↗

PubMed2004

The human plasma proteome: a nonredundant list developed by combination of four separate sources.

We have merged four different views of the human plasma proteome, based on different methodologies, into a single nonredundant list of 1175 distinct gene products. The methodologies used were 1) literature search for proteins reported to occur in plasma or serum; 2) multidimensional chromatography of proteins followed by two-dimensional electrophoresis and mass spectroscopy (MS) identification of resolved proteins; 3) tryptic digestion and multidimensional chromatography of peptides followed by MS identification; and 4) tryptic digestion and multidimensional chromatography of peptides from low-molecular-mass plasma components followed by MS identification. Of 1,175 nonredundant gene products, 195 were included in more than one of the four input datasets. Only 46 appeared in all four. Predictions of signal sequence and transmembrane domain occurrence, as well as Genome Ontology annotation assignments, allowed characterization of the nonredundant list and comparison of the data sources. The "nonproteomic" literature (468 input proteins) is strongly biased toward signal sequence-containing extracellular proteins, while the three proteomics methods showed a much higher representation of cellular proteins, including nuclear, cytoplasmic, and kinesin complex proteins. Cytokines and protein hormones were almost completely absent from the proteomics data (presumably due to low abundance), while categories like DNA-binding proteins were almost entirely absent from the literature data (perhaps unexpected and therefore not sought). Most major categories of proteins in the human proteome are represented in plasma, with the distribution at successively deeper layers shifting from mostly extracellular to a distribution more like the whole (primarily cellular) proteome. The resulting nonredundant list confirms the presence of a number of interesting candidate marker proteins in plasma and serum.

Biomarkers, Tumor↗

PubMed1996

Major transmembrane movement associated with colicin Ia channel gating.

Colicin Ia, a bacterial protein toxin of 626 amino acid residues, forms voltage-dependent channels in planar lipid bilayer membranes. We have exploited the high affinity binding of streptavidin to biotin to map the topology of the channel-forming domain (roughly 175 residues of the COOH-terminal end) with respect to the membrane. That is, we have determined, for the channel's open and closed states, which parts of this domain are exposed to the aqueous solutions on either side of the membrane and which are inserted into the bilayer. This was done by biotinylating cysteine residues introduced by site-directed mutagenesis, and monitoring by electrophysiological methods the effect of streptavidin addition on channel behavior. We have identified a region of at least 68 residues that flips back and forth across the membrane in association with channel opening and closing. This identification was based on our observations that for mutants biotinylated in this region, streptavidin added to the cis (colicin-containing) compartment interfered with channel opening, and trans streptavidin interfered with channel closing. (If biotin was linked to the colicin by a disulfide bond, the effects of streptavidin on channel closing could be reversed by detaching the streptavidin-biotin complex from the colicin, using a water-soluble reducing agent. This showed that the cysteine sulfur, not just the biotin, is exposed to the trans solution). The upstream and downstream segments flanking the translocated region move into and out of the bilayer during channel opening and closing, forming two transmembrane segments. Surprisingly, if any of several residues near the upstream end of the translocated region is held on the cis side by streptavidin, the colicin still forms voltage-dependent channels, indicating that a part of the protein that normally is fully translocated across the membrane can become the upstream transmembrane segment. Evidently, the identity of the upstream transmembrane segment is not crucial to channel formation, and several open channel structures can exist.

Bacterial Proteins↗

PubMed2006

Intramembrane proteolysis mediates shedding of a key adhesin during erythrocyte invasion by the malaria parasite.

Apicomplexan pathogens are obligate intracellular parasites. To enter cells, they must bind with high affinity to host cell receptors and then uncouple these interactions to complete invasion. Merozoites of Plasmodium falciparum, the parasite responsible for the most dangerous form of malaria, invade erythrocytes using a family of adhesins called Duffy binding ligand-erythrocyte binding proteins (DBL-EBPs). The best-characterized P. falciparum DBL-EBP is erythrocyte binding antigen 175 (EBA-175), which binds erythrocyte surface glycophorin A. We report that EBA-175 is shed from the merozoite at around the point of invasion. Shedding occurs by proteolytic cleavage within the transmembrane domain (TMD) at a site that is conserved across the DBL-EBP family. We show that EBA-175 is cleaved by PfROM4, a rhomboid protease that localizes to the merozoite plasma membrane, but not by other rhomboids tested. Mutations within the EBA-175 TMD that abolish cleavage by PfROM4 prevent parasite growth. Our results identify a crucial role for intramembrane proteolysis in the life cycle of this pathogen.

Animals↗

PubMed2000

The amino acid/polyamine/organocation (APC) superfamily of transporters specific for amino acids, polyamines and organocations.

In this paper an analysis of 175 currently sequenced transport proteins that comprise the amino acid/polyamine/organocation (APC) superfamily is reported. Members of this superfamily fall into 10 well-defined families that are either prokaryote specific, eukaryote specific or ubiquitous. Most of these proteins exhibit 12 probable transmembrane spanners (TMSs), but members of two of these families deviate from this pattern, exhibiting 10 and 14 TMSs. All members of these families are tabulated, their functional properties are reviewed and phylogenetic/sequence analyses define the evolutionary relationships of the proteins to each other. Evidence is presented that the APC superfamily may include two other currently recognized families that exhibit greater degrees of sequence divergence from APC superfamily members than do the proteins of the 10 established families from each other. At least some of the protein members of these two distantly related families exhibit 11 established TMSs. Altogether, the APC superfamily probably includes 12 currently recognized families with members that exhibit exclusive specificity for amino acids and their derivatives but which can possess 10, 11, 12 or 14 TMSs per polypeptide chain.

Amino Acid Sequence↗

PubMed2003

Is the olfactory receptor a metalloprotein?

The sense of smell is arguably our most primal faculty and also the least understood. Even our own olfactorily impaired species is capable of detecting approximately 10,000 distinct scents [Buck, L. & Axel, R. (1991) Cell 65, 175-187]. To achieve that amazing diversity, mammals have approximately 1,000 olfactory genes, which accounts for approximately 3% of their entire genome [Mombaerts, P. (1999) Science 286, 707-711]. The olfactory receptors (ORs) are believed to be seven-helix transmembrane proteins, with an odorant-binding site on the periplasmic domain and a G protein-binding site on the cytoplasmic domain. Odorants first bind to an OR, which then undergoes some structural change that triggers the G protein activation and the following cascade of events leading to nerve cell activity. The structural details of ORs, however, remain to be determined. In this paper, we will describe a hypothesis in which metal ions play an important role for odorant recognition. We analyze the predicted structure and consensus sequence of the ORs and propose a metal-binding site in the loop between fourth and fifth helix (4-5 loop). We have prepared synthetically a pentapeptide that contains this putative binding site and find that it not only has high affinity for binding Cu(II) and Zn(II) ions, but that it also undergoes a dramatic transition to an alpha-helical structure upon metal ion binding. Based on these observations, we propose a "shuttlecock" mechanism for the possible structural change in ORs upon odorant binding. This mechanism involves membrane penetration of the 4-5 loop after residue charge neutralization by metal ion binding.

Amino Acid Sequence↗

PubMed1998

Conformation and ion-channeling activity of a 27-residue peptide modeled on the single-transmembrane segment of the IsK (minK) protein.

IsK (minK) protein, in concert with another channel protein KVLQT1, mediates a distinct, slowly activating, voltage-gated potassium current across certain mammalian cell membranes. Site-directed mutational studies have led to the proposal that the single transmembrane segment of IsK participates in the pore of the potassium channel [Takumi, T. (1993) News Physiol. Sci. 8, 175-178]. We present functional and structural studies of a short peptide (K27) with primary structure NH2-1KLEALYILMVLGFFGFFTLGIMLSYI27R-COOH, corresponding to the transmembrane segment of IsK (residues 42-68). When K27 was incorporated, at low concentrations, into phosphatidylethanolamine, black-lipid membranes, single-channel activity was observed, with no strong ion selectivity. IR measurements reveal the peptide has a predominantly helical conformation in the membrane. The atomic resolution structure of the helix has been established by high-resolution 1H NMR spectroscopy studies. These studies were carried out in a solvent comprising 86% v/v 1,1,1,3,3,3-hexafluoro-isopropanol-14% v/v water, in which the IR spectrum of the peptide was found to be very similar to that observed in the bilayer. The NMR studies have established that residues 1-3 are disordered, while residues 4-27 have an alpha-helical conformation, the helix being looser near the termini and more stable in the central region of the molecule. The length (2. 6 nm) of the hydrophobic segment of the helix, residues 7-23, matches the span of the hydrocarbon chains (2.3 +/- 0.25 nm) of fully hydrated bilayers of phosphatidylcholine lipid mixture from egg yolk. The side chains on the helix surface are predominantly hydrophobic, consistent with a transmembrane location of the helix. The ion-channeling activity is believed to stem from long-lived aggregates of these helices. The aggregation is mediated by the pi-pi stacking of phenylalanine aromatic rings of adjacent helices and favorable interactions of the opposing aliphatic-like side chains, such as leucine and methionine, with the lipid chains of the bilayer. This mechanism is in keeping with site-directed mutational studies which suggest that the transmembrane segment of IsK is an integral part of the pore of the potassium channel and has a similar disposition to that in the peptide model system.

Amino Acid Sequence↗

PubMed2005

Non-synaptic mechanisms underlie the after-effects of cathodal transcutaneous direct current stimulation of the human brain.

Although cathodal transcranial direct current stimulation (tDCS) decreases cortical excitability, the mechanisms underlying DC-induced changes remain largely unclear. In this study we investigated the effect of cathodal DC stimulation on spontaneous neural activity and on motor responses evoked by stimulation of the central and peripheral nervous system. We studied 17 healthy volunteers. Transcranial magnetic stimulation (TMS) and transcranial electrical stimulation (TES) of the motor area were used to study the effects of cathodal tDCS (1.5 mA, 10 min) on resting motor threshold and motor evoked potentials (MEPs) recorded from the contralateral first dorsal interosseous muscle (FDI). The electroencephalographic (EEG) activity in response to cathodal tDCS was analysed by power spectral density (PSD). Motor axonal excitability changes in response to transcutaneous DC stimulation of the ulnar nerve (0.3 mA, 10 min) were assessed by testing changes in the size of the compound muscle action potential (CMAP) elicited by submaximal nerve stimulation. Cathodal tDCS over the motor area for 10 min increased the motor threshold and decreased the size of MEPs evoked by TMS for at least 60 min after current offset (t(0) 71.7 +/- 5%, t(20) 50.8 +/- 11%, t(40) 47.7 +/- 7.7%, and t(60) 39.7 +/- 6.4%, P < 0.01). The tDCS also significantly decreased the size of MEPs elicited by TES (t(0) 64 +/- 16.4%, P = 0.09; t(20) 67.6 +/- 10.8%, P = 0.06; and t(40) 58.3 +/- 9.9%, P < 0.05). At the same time in the EEG the power of delta (2-4 Hz) and theta (4-7 Hz) rhythms increased (delta 181.1 +/- 40.2, P < 0.05; and theta 138.7 +/- 27.6, P = 0.07). At the peripheral level cathodal DC stimulation increased the size of the ulnar nerve CMAP (175 +/- 34.3%, P < 0.05). Our findings demonstrate that the after-effects of tDCS have a non-synaptic mechanism of action based upon changes in neural membrane function. These changes apart from reflecting local changes in ionic concentrations, could arise from alterations in transmembrane proteins and from electrolysis-related changes in [H(+)] induced by exposure to constant electric field.

Adult↗

PubMed2002

Molecular cloning and functional expression of the rat 175-kDa hyaluronan receptor for endocytosis.

We recently purified the rat liver hyaluronan receptor for endocytosis (HARE) and found abundant expression of 175- and approximately 300-kDa HARE species in sinusoidal endothelial cells of the liver, spleen, and lymph nodes. We report herein the first cloning and functional expression of the rat 175-kDa HARE. Peptide sequences were obtained from the purified 175-kDa HARE, and degenerate oligonucleotide primers were designed for reverse transcription-polymerase chain reaction and cDNA cloning. Results of 5'-rapid amplification of cDNA ends, Northern analysis, N-terminal sequence, and antibody reactivity analyses indicated the absence of mRNA directly encoding the 175-kDa HARE. This protein is most likely derived from a larger precursor. Accordingly, we constructed an artificial 4.7-kb cDNA encoding the 1431 amino acid 175-kDa HARE. The predicted type I membrane protein has a mass of 156,393 Da and a pI of 7.86. The 175-kDa HARE cDNA, fused to the N-terminal leader sequence of the Ig kappa-chain, was transfected transiently into COS-7 cells and stably into SK-Hep-1 cells, respectively, to assess hyaluronan or hyaluronic acid (HA)-binding activity and endocytosis. In both cases, HARE expression and HA-binding activity were detected. Furthermore, stable SK-175HARE cells demonstrated specific endocytosis of (125)I-HA and receptor recycling. Fluorescence-activated cell sorting analysis confirmed that recombinant HARE was expressed on the cell surface and that fluorescent HA uptake was inhibited by a specific blocking monoclonal antibody against HARE. Additionally, HARE was substantially colocalized with clathrin, but not with internalized HA that was delivered to lysosomes. The results confirm that recombinant 175-kDa HARE is an authentic endocytic receptor for HA and that this receptor can function independently of the approximately 300-kDa HARE. HARE is the first functionally identified member of a protein family that shares a similar organization of Fasciclin, epidermal growth factor-like, Xlink, and transmembrane domains.

Amino Acid Sequence↗