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PubMed1978

Hepatic alpha-adrenergic receptors. Identification and subcellular localization using [3H]dihydroergocryptine.

Recently, several workers have shown that adrenergic control of hepatic carbohydrate metabolism has the characteristics of an alpha-receptor-mediated process. Using the rat liver membrane preparation of Neville (Neville, D. (1968) Biochim. Biophys. Acta 154, 540-552), alpha-adrenergic receptors have been identified using the ligand [3H]dihydroergocryptine. The receptors are saturable and of high affinity. Scatchard analysis yields a KD of 1.8 nM with 1.7 +/- 0.55 pmol of sites/mg of protein. Competition of dihydroergocryptine binding with various pharmacologic agents yields the typical (alpha-adrenergic potency series: (-)-epinephrine greater than (-)-norepinephrine greater than (-)-isoproterenol. (-)-Isomers are more potent than (+)-isomers. The alpha-blocker phentolamine is 3.4 orders of magnitude more potent than the beta-blocker propranolol. To determine subcellular localization of alpha-adrenergic receptors, livers were fractionated into a crude homogenate, a 1500 X g pellet, and the purified membrane preparation used previously for binding. Specific dihydroergocryptine binding, ouabain-inhibitable (Na,K)-ATPase, and F--stimulated adenylate cyclase activities, were followed in these fractions. Specific binding was enriched, relative to that in the crude homogenate, 2.88-fold in the pellet and 6.28-fold in the membranes. Similarly, (Na,K)-ATPase acticity was enriched 2.6-fold in the pellet and 7.1-fold in the membranes while adenylate cyclase activity was enriched 2.9-fold in the pellet and 3.5-fold in the membranes. It is concluded that hepatic alpha-adrenergic receptors are likely concentrated in the plasma membranes.

Adenylyl Cyclases↗

PubMed1989

Protamine 3'-untranslated sequences regulate temporal translational control and subcellular localization of growth hormone in spermatids of transgenic mice.

Although the mouse protamine 1 gene (mP1) is first transcribed in round spermatids, its mRNA is not translated until about 1 week later in elongating spermatids. To determine what mP1 sequences are important for its transcriptional and translational regulation, we have constructed fusions between mP1 and the human growth hormone (hGH) structural gene and analyzed their expression in transgenic mice. We show that mP1 sequences 5' to the start of transcription are sufficient to confer spermatid-specific expression on the hGH gene. We also show that 156 nucleotides of mP1 3'-untranslated sequence is sufficient to confer mP1-like translational regulation on the hGH mRNA. Interestingly, the subcellular localization of hGH was dependent on the time during spermiogenesis that it was made. Synthesis of hGH in early round spermatids resulted in localization in the acrosome, whereas synthesis in late elongating spermatids resulted in intracellular, but not acrosomal, localization.

Acrosome↗

PubMed1987

Subcellular localization of sulfated glucuronic acid-containing glycolipids reacting with anti-myelin-associated glycoprotein antibody.

Peripheral nerve glycolipids, with which anti-myelin-associated glycoprotein (MAG) antibodies from patients with demyelinating neuropathy and plasma cell dyscrasia cross-react, proved to be novel glycosphingolipids containing a sulfated glucuronyl residue. Consequently, there has been much interest in the immunological role that these sulfated glucuronyl-glycosphingolipids (SGGLs) may play in the pathogenesis of this disorder. For the determination of the distribution of these glycolipids in various nervous tissues and, thereby, the elucidation of their pathogenicity, a quantitative immunostaining-TLC method for their detection has been devised. Using this method, we demonstrated that these glycolipids were distributed in greatly different amounts in the peripheral nerves from human, bovine, chicken, rat, and rabbit. Subcellular localization studies of bovine peripheral nerve also demonstrated that they were enriched in the axolemma-enriched fraction and present in glial-related membranes in lower concentrations. In addition, these glycolipids were present in bovine dura mater and transformed rat Schwann cells. These biochemical results suggest that not only myelin but also axons could be involved as targets of the anti-MAG antibody in macroglobulinemia neuropathy, and it may also be necessary to examine anti-SGGL activity in patients with axonal neuropathy associated with plasma cell dyscrasia.

Animals↗

PubMed1978

Biosynthesis and subcellular localization of histamine in H-110 lymphoma.

The histidine decarboxylase activity has been studied in the H-110 Lymphoma implanted in Balb-c mice. The enzymatic activity has been determined using DL-Histidine 1-14C by measuring the I--14CO2 liberated during the incubation. It has been found that the histidine decarboxylase activity in the tumor is the highest of the studied tissues. The pretreatment for 5 days with two cytostatic drugs, cyclophosphamide and 5-fluoruracile, determined a decrease of the enzymatic activity in the tumor of 33 and 54 per cent, respectively. This effect has not been observed in the lung. The pretreatment of the animals during 10 days with 0.1 mg per kg body of histamine, which in other experimental tumors induces an increase of the endogenous content of histamine, produces a decrease of the tumoral histidine decarboxylase activity. The histamine-14C uptake was not modified by this pretreatment. The subcellular localization of the radioactivity after pretreatment with histamine-14C evidenced that the nuclear fraction of the tumor contained between 2 and 10 times the radioactivity of other tissues of the same animal.

Animals↗

PubMed1989

Differential expression and subcellular localization for subunits of cAMP-dependent protein kinase during ram spermatogenesis.

The expression of mRNAs for the RI alpha, RII alpha, and C alpha subunits of cAMP-dependent protein kinase has been studied in different ram germ cells. The sizes of the specific RI alpha, RII alpha, and C alpha mRNAs, observed in germ cells were 1.6, 2.0, and 2.6 kb, respectively. RI alpha and C alpha mRNAs were mainly expressed in primary spermatocytes. A postmeiotic expression predominating in early spermatids was unique to RII alpha mRNA. The location of RI, RII alpha, and C subunits in well-defined organelles of ram spermatids and epididymal sperm was assessed by immunogold electron microscopy. In spermatids, RI, RII alpha, and C were essentially present in the forming acrosome and, to a lesser extent, in the nucleus. During sperm epididymal maturation, the protein kinases disappeared from the acrosome and were detected in a variety of sperm functional areas, such as the tip of the acrosome, the motility apparatus, and the membrane network. The present study on subunits of cAMP-dependent protein kinase supports the concept that specific functions are attached to the different subunits in that it shows differential expression and differential subcellular localization in germ cells.

Animals↗

PubMed1990

Functional domains of the HIV-1 rev gene required for trans-regulation and subcellular localization.

The rev gene of human immunodeficiency virus type 1 (HIV-1) encodes a 116 amino acid nuclear regulatory protein (Rev) that increases the cytoplasmic expression of viral mRNAs containing the Rev response element (RRE) and coding for the structural proteins, Gag and Env. To identify the functional domains of Rev, amino acid deletion and chain termination mutations were introduced in the Rev coding region. The ability of these mutants to increase the cytoplasmic expression of a Rev-test plasmid (pSV-AR), containing the RRE cloned into the 3' noncoding region of the CAT gene in plasmid pSV2CAT, was examined in transient expression assays in HeLa cells. Our results indicate that three distinct regions mapping within the N-terminal 98 amino acids of Rev are essential for its activity. The subcellular localization of the various Rev proteins was examined in COS cells by indirect immunofluorescence. Rev was found to localize predominantly in the nucleolus of transfected cells. All mutant Rev proteins, with the exception of a deletion mutant (rev delta 41-44) lacking four Arg residues of a highly basic domain, were found to localize in the nucleolus. Mutant rev delta 41-44 exhibited weak diffuse fluorescence in the nucleus with a tendency to accumulate in the cytoplasm. A 15 amino acid region encompassing this basic domain (38-52) when fused to the Escherichia coli beta-galactosidase gene efficiently directed the fusion gene product to the nucleus and nucleolus, suggesting a role for this domain in the nucleolar localization of Rev.

Amino Acid Sequence↗

PubMed1992

Differential expression and subcellular localization of secretogranin II and synaptophysin during early development of mouse hypothalamic neurons in culture.

Mature neurons contain two distinct regulated secretory pathways, characterized electron microscopically by so-called large dense core vesicles and small synaptic vesicles, respectively. Each vesicle type is characterized by vesicle-specific proteins, such as the granins (chromogranins/secretogranins) for the matrix of large dense core vesicles and synaptophysin for the membrane of small synaptic vesicles. So far, no data exist on the biogenesis of these two distinct vesicle types during neuronal development. We have used secretogranin II and synaptophysin as markers for the biogenesis of these two vesicle types during the development of mouse hypothalamic neurons in culture, using immunocytochemistry and biochemical analyses. By immunofluorescence, we found that secretogranin II appears as early as synaptophysin, but in a subset of neurons only, and with different subcellular localizations. It was observed in cytoplasmic areas where little or no synaptophysin immunofluorescence was detected, such as lamellipodia, emerging neurites and growth cones. At later stages, the proportion of secretogranin II-containing varicosities remained steady whereas that of synaptophysin-containing varicosities increased dramatically. By quantitative analysis we found that the level of expression of synaptophysin increased several-fold during synaptogenesis whereas that of secretogranin II decreased. These data suggest that large dense core vesicles and small synaptic vesicles can be formed separately and expressed at different levels. They provide evidence for a differential biogenesis of these two distinct vesicle types.

Animals↗

PubMed1990

Cellular and subcellular localization of an Mr 64,000 protein autoantigen in insulin-dependent diabetes.

Antibodies to an Mr 64,000 protein from human or rat islets have been detected at high frequency in newly diagnosed insulin-dependent diabetic patients. In this study, we show that the antigenic and amphiphilic properties of the rat islet Mr 64,000 protein resemble that of the human protein. We have analyzed the expression of the Mr 64,000 protein in populations of pancreatic beta and non-beta cells and in selected rat tissues by immunoprecipitation of [35S]methionine-radiolabeled proteins with sera from diabetic patients or from healthy control individuals. When islet cell populations enriched in beta or non-beta cells were tested for the expression of the Mr 64,000 antigen, the protein was primarily observed in the beta cells. On analyzing preparations of islets, liver, kidney, thyroid, adrenal, pituitary, spleen, and thymus, the protein could only be detected in islets. The protein was also characterized in terms of its subcellular localization by Percoll density gradient centrifugation and was recovered in a fraction enriched in the plasma membrane marker, 5'-nucleotidase. These results are consistent with a beta cell-restricted plasma membrane expression of the protein and support the hypothesis that this protein is a target antigen of beta cell-specific autoimmunity in insulin-dependent diabetes.

Animals↗

PubMed1985

Further characterization and subcellular localization of Sm and U1 ribonucleoprotein antigens.

Sera from patients with systemic autoimmune diseases often contain antibodies against small nuclear ribonucleoprotein (snRNP) particles. Anti-Sm antibodies react with the entire set of U1, U2, U4, U5 and U6 (U1-U6) RNP particles whereas anti-(U1)RNP sera specifically recognize particles containing U1 RNA. Here we performed semi-quantitative immunoblotting using 16 human anti-Sm, 15 human anti-(U1)RNP sera and two mouse monoclonal antibodies to establish which snRNA-associated proteins carry antigenic determinants. Almost every (15/16) human anti-Sm sera recognized epitopes present on a 28-kDa (B/B') protein doublet and on a 16-kDa (D) polypeptide. Nine anti-(U1)RNP sera also recognized the B/B' doublet, but in all cases a much stronger reaction was observed with one or more of the specifically U1 RNA-associated 70 kDa, A or C antigens. With affinity-purified antibody fractions eluted from individual antigen bands on nitrocellulose blots it is shown that the anti-Sm-reactive polypeptides B/B' and D contain common epitopes. We also report the finding of one human anti-Sm serum with exclusive specificity for the B/B' doublet and a mouse monoclonal anti-Sm antibody recognizing only the D protein, indicating that these antigens also carry unique epitopes. In immunoprecipitation assays, purified anti-B/B' and -D antibodies react with (U1-U6) RNP while purified anti-70 kDa, anti-A and anti-C antibodies precipitate exclusively U1 RNP particles. Finally, we established the subcellular localization of Sm and U1 RNP antigens using a biochemical cell fractionation procedure. Part of the 70 kDa and B/B' antigens were found in a nuclease and high salt-resistant nuclear substructure, usually referred to as nuclear matrix, while the A and D antigens could be extracted completely from HeLa nuclei by ribonuclease treatment and subsequent high salt extraction.

Antibody Specificity↗

PubMed1991

Dystrophin in central nervous system: a developmental, regional distribution and subcellular localization study.

Dystrophin, the protein encoded by the Duchenne muscular dystrophy gene has been shown to be expressed in central nervous system. In the present study, polyclonal antibodies raised against 3 fusion proteins constructed from different structural domains of dystrophin were used to identify dystrophin in protein extracts from rat and mdx mouse brain. The developmental expression of the protein, its regional distribution in rat brain and its localization in rat brain subcellular fractions were also examined. We found that dystrophin or a 'dystrophin-related protein' is expressed in mdx mouse brain. Dystrophin is detectable at very early stages of rat brain development and is expressed in all adult brain regions examined, although quantitative regional differences were found. Subcellular distribution analysis indicates that dystrophin is absent in mitochondrial and synaptic vesicle-enriched fractions but is recovered in the synaptic plasma membrane fraction.

Animals↗

PubMed1979

Physiological disposition and subcellular localization of 14C-fenclorac in the rat.

The physiologic disposition and subcellular tissue localization of 14C-fenclorac was studied in rats receiving single and multiple oral doses of the drug. The drug was primarily excreted via renal and fecal routes. The 24-hour urinary and fecal elimination rates were 41 and 17% respectively, of the administered dose. The daily elimination rates of drug/drug metabolites were not altered when the treatment period was extended to seven days, suggesting that the processes for the renal and fecal clearance of drug were not affected by this treatment schedule. Studies on the distribution of 14C-fenclorac in slected tissues revealed that hepatic, renal and splenic tissue to plasma ratio of the label twenty-four hours after a single dose was 1.53, 3.88 and 0.11, respectively. Similar results were observed in rats receiving multiple doses of 14C-fenclorac. The 14C-label was distributed throughout the subcellular organelles with the highest concentration in the cytosol and lower levels in the mitochondria and microsomes. Furthermore, these experiments demonstrated that both metabolic (hepatic) and excretory (kidney) organs do not accumulate fenclorac in animals receiving the drug up to seven days.

Animals↗

PubMed1988

Subcellular localization of Gi alpha in human neutrophils.

Subcellular fractions were prepared from human neutrophils by sucrose density gradient centrifugation and analyzed for Gi-like proteins by pertussis toxin-catalyzed [32P]ADP-ribosylation and by immunoblotting with rabbit antiserum AS/6 which recognizes purified transducin and Gi, but not Gs or Go alpha-subunits. In resting cells, approximately equal to 60% of pertussis toxin substrate retrieved from the sucrose density gradient localized to the plasma membrane-enriched fraction, approximately equal to 35% to the specific granule-enriched fraction, and approximately equal to 5% to cytosol. The azurophil granule-enriched fraction did not contain pertussis toxin substrate. In contrast to plasma membrane, the specific granule-enriched fraction demonstrated increased AS/6 immunoreactivity of a approximately equal to 41-kDa protein relative to a approximately equal to 40-kDa protein. Within the specific granule-enriched fraction, the peak of pertussis toxin substrate detected immunochemically or by [32P]ADP-ribosylation sedimented at a lighter density (rho = 1.6 g/ml) than did lactoferrin (rho = 1.19 g/ml), suggesting that the intracellular compartment bearing pertussis toxin substrate may not be the lactoferrin containing specific granule, per se. Furthermore, in neutrophils exposed to 10(-8) M N-formylmethionylleucylphenylalanine, a weak degranulating stimulus (7% lactoferrin degranulation), there was a 31-42% decline in pertussus toxin-catalyzed [32P]ADP-ribosylation of approximately equal to 40-41-kDa proteins in the specific granule-enriched fraction accompanied by a near-quantitative increase in labeling of plasma membrane. The pool of intracellular formyl peptide receptors localized to the specific granule-enriched fraction appeared functionally coupled to a cosedimenting G-protein in experiments demonstrating modulation of high affinity N-formylmethionylleucyl[3H]phenylalanine binding by guanosine 5'-(3-O-thio)triphosphate or pertussis toxin. The data indicate that neutrophils contain a surface translocatable pool of intracellular G-protein sedimenting in the specific granule-enriched fraction and support the view that mobilization of intracellular G-protein represents a mechanism by which cells can regulate receptor activity.

Adenosine Diphosphate Ribose↗

PubMed1985

Subcellular localization of histone messenger RNAs on cytoskeleton-associated free polysomes in HeLa S3 cells.

We have examined the subcellular distribution of histone mRNA-containing polysomes in HeLa S3 cells to assess the possible relationship between localization of histone mRNAs and the regulation of cellular histone mRNA levels. The distribution of histone mRNAs on free and membrane bound polysomes was examined as well as the association of histone mRNA-containing polysomes with the cytoskeleton. The subcellular localization of histone mRNAs was compared with that of HLA-B7 mRNAs which encode a cell surface antigen. Histone mRNAs were localized predominantly on the free polysomes, whereas the HLA-B7 mRNA was found almost exclusively on membrane bound polysomes. However, both species of mRNA were found associated with the cytoskeleton. Interruption of DNA synthesis by hydroxyurea treatment resulted in a rapid and selective destabilization of histone mRNAs in each subcellular fraction; in contrast, the stability of HLA-B7 mRNA appeared unaffected. The results presented confirm that histone mRNAs are predominantly located on non-membrane bound polysomes and suggest that these polysomes are associated with the cytoskeletal framework.

Cycloheximide↗

PubMedDate not supplied

Acetylcholinesterase and nonspecific cholinesterase activities in rat liver: subcellular localization, molecular forms, and some extraction properties.

Subcellular distribution and some extraction properties of acetylcholinesterase (AchE) (EC 3.1.1.7) and nonspecific cholinesterase (ChE) (EC 3.1.1.8) were studied in rat liver employing subcellular fractionation techniques. All purified subcellular fractions were enriched in total cholinesterase activity over the homogenate. Plasma membrane and Golgi fractions showed a significant enrichment in AchE activity, while ChE activity was enriched in both rough and smooth endoplasmic reticulum. Subcellular fractions were subjected to conditions that selectively release proteins having varying degrees of association to membranes. High-pH treatment (known to release peripheral and soluble proteins) extracted ChE activity, but more than 90% of AchE activity remained associated to the pellet. Solubility properties and molecular forms of AchE and ChE in this tissue were studied by extraction in high-salt medium with and without Triton X-100, followed by velocity sedimentation centrifugation. Most of AchE activity (88%) (41% G4 and 59% G2 + G1) was detergent soluble; 42% of ChE activity (detected only as G2 + G1) was high-salt soluble, whereas remaining ChE activity was detergent soluble. These results indicate not only a different subcellular location for both enzymes, but also point to a differential association to membranes. AchE behaves as an integral membrane protein and ChE behaves as a peripheral or a luminal soluble protein.

Acetylcholinesterase↗

PubMed1989

Axolinin localization in the nervous tissue of squid revealed by monoclonal antibodies specific for axolinin: cellular and subcellular localization of axolinin in the squid neuron.

Cellular and subcellular distributions of axolinin, the 260-kilodalton (kD) microtubule-associated glycoprotein originally purified from squid axons, in various squid tissues such as optical lobes, bundles of small nerve fibers (fin nerves), giant stellate ganglia, skin, muscle, liver, and gill, were immunologically studied using monoclonal antibodies specifically recognizing the polypeptide chain of axolinin. The following results were obtained: (1) Axolinin is confined to squid neurons and skin; (2) axolinin is localized in the axon whereas another 260-kD microtubule-associated protein, MAP B, is localized in the cell bodies; and (3) axolinin is localized mainly in the peripheral part of the axoplasm of the squid giant axon. The last result has confirmed our previous conclusion obtained using polyclonal antisera against axolinin, which contain antibodies recognizing not only axolinin-specific epitopes but also nonspecific epitopes. The physiological importance of the localization of axolinin in axons and the skin is discussed based on its possible relationship to excitability function.

Animals↗

PubMed1992

The regional, cellular and subcellular localization of GABAA/benzodiazepine receptors in the substantia nigra of the rat.

The regional, cellular and subcellular distribution of GABAA/benzodiazepine receptors was investigated by light and electron microscopy in the rat substantia nigra. The regional distribution and density of GABAA/benzodiazepine receptor subtypes (Type I and II) was studied using quantitative receptor autoradiography following in vitro labelling of cryostat sections with tritiated ligands. This was followed by a detailed study of the cellular and subcellular distribution and localization of GABAA/benzodiazepine receptors by light and electron microscopy using immunohistochemical techniques with a monoclonal antibody (bd-17) to the beta 2,3 subunits of the GABAA/benzodiazepine receptor complex. Finally, in situ hybridization histochemistry using 35S-labelled oligonucleotide probes was used to demonstrate the cellular distribution of mRNA for the alpha 1 and alpha 2 GABAA receptor subunits in the substantia nigra. The results of the autoradiographic and immunohistochemical studies showed a close correspondence in the regional distribution of GABAA/benzodiazepine receptors in the substantia nigra. A moderate-to-high density of receptors was present throughout the full extent of the substantia nigra pars reticulata with a very low density of receptors in the substantia nigra pars compacta. Quantitative autoradiographic studies showed that: (i) the pars reticulata contained mainly central Type I receptors; (ii) the highest density of receptors was present in the caudal pars reticulata (200 +/- 38 fmol/mg) with successively lower densities of receptors in the middle (176 +/- 31 fmol/mg) and rostral (150 +/- 26 fmol/mg) levels of the pars reticulata; and (iii) the density of receptors in the pars reticulata was reduced by 34% following 6-hydroxydopamine-induced degeneration of dopaminergic pars compacta neurons. At the cellular level, GABAA/benzodiazepine receptor immunoreactivity was localized in a punctate fashion on dendrites and neuronal cell bodies in the pars reticulata. At the subcellular level, GABAA/benzodiazepine receptor immunoreactivity was associated with the pre- and postsynaptic membranes of axodendritic synaptic complexes along the length of small-to-large sized smooth dendrites in the pars reticulata. Two types of immunoreactive axodendritic synaptic complexes were identified: most (about 80%) immunopositive synapses showed equal staining of the pre- and postsynaptic membranes and were associated with small (less than 1.0 micron) axon terminals containing few mitochondria and small, round-to-pleomorphic vesicles in synaptic contact with small, peripheral dendrites; less frequently (about 20%) immunopositive synapses showed a marked immunoreactive thickening of the postsynaptic membrane and were associated with large (greater than 1.0 micron) axon terminals containing numerous mitochondria and mainly pleomorphic vesicles in synaptic contact with large mainstem dendrites.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

PubMed1987

Subcellular localization of cholesterol ester hydrolase in the human intestine.

Immunocytochemistry and subcellular fractionation were used to localize the cholesterol ester hydrolase in the human small intestine. A positive immunoreaction, when using antibodies directed against pancreatic cholesterol ester hydrolase, was mainly found in endocytotic vesicles. Moreover, a label by gold particles was observed in intercellular spaces where lymphatic tissue merges. No specific immunoreactivity was obtained with the mucosa when sera directed against human pancreatic chymotrypsinogen and human pancreatic lipase were used. Conventional subcellular fractionation was performed after extensive washing of enterocytes to rule out any possible contamination by pancreatic enzymes. In these conditions a bile salt-dependent cholesterol ester hydrolase activity was detected in the soluble fraction of cells. Data agree with the concept that the intestinal cholesterol ester hydrolase may have a pancreatic origin. The absorption, if any, of this enzyme by enterocytes seems specific since other pancreatic (pro)enzymes tested (lipase, chymotrypsinogen) are not detected in these cells.

Adult↗

PubMed1985

Subcellular localization of renal kallikrein by ultrastructural immunocytochemistry.

The subcellular distribution of immunoreactive kallikrein was described in the rat nephron using ultrastructural immunocytochemistry. The renal tissue was fixed with a mixture of buffered picric acid-paraformaldehyde-glutaraldehyde and immunostained with the peroxidase-antiperoxidase method for the electron microscope with the following steps: antikallikrein antiserum, anti-IgG serum, peroxidase-antiperoxidase complex, 3-3' diaminobenzidine-H2O2, and post-staining with osmium tetroxide. Preabsorption of the primary antiserum with purified rat urinary kallikrein and substitution with normal serum were used as controls. As we have described previously, kallikrein was present exclusively in the connecting tubule cell of the distal nephron. Subcellularly, kallikrein was distributed in luminal membranes, basal membranes, rough endoplasmic reticulum, Golgi apparatus, and vesicles. The immunoreactive vesicles were present in the proximity of the Golgi apparatus and in the cytoplasm in the way between the Golgi and the luminal and basal plasma membranes. No immunostaining was observed in other subcellular components of the connecting tubule cell or in the other type of cell. With the description of kallikrein in subcellular organelles involved in the synthesis, processing, and transport of glycoproteins, we have advanced an hypothetical intracellular processing pathway for renal kallikrein.

Animals↗