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20-577: CPZ may refer to: CPZ (gene) , a gene coding for the enzyme carboxypeptidase Z CPZ: an EEG electrode site according to the 10-20 system Circuit Park Zandvoort , a motorsport track near Zandvoort, the Netherlands Continuous permafrost zone , an area where permafrost cannot thaw Controlled parking zone , a type of UK parking restriction Chlorpromazine , an antipsychotic drug Compass Airlines (North America) (ICAO designator),
40-522: A gene on human chromosome 4 is a stub . You can help Misplaced Pages by expanding it . Isoforms A protein isoform , or " protein variant ", is a member of a set of highly similar proteins that originate from a single gene and are the result of genetic differences. While many perform the same or similar biological roles, some isoforms have unique functions. A set of protein isoforms may be formed from alternative splicings , variable promoter usage, or other post-transcriptional modifications of
60-539: A U.S. airline Corner Patrol Zone , a type of hazard in the Robot Wars Arena Zoos Capron Park Zoo , Attleboro, Massachusetts Central Park Zoo , Manhattan, New York City Charles Paddock Zoo , San Luis Obispo County, California Topics referred to by the same term [REDACTED] This disambiguation page lists articles associated with the title CPZ . If an internal link led you here, you may wish to change
80-434: A gene that serves as an initial binding site—resulting in slightly modified transcripts and protein isoforms. Generally, one protein isoform is labeled as the canonical sequence based on criteria such as its prevalence and similarity to orthologous —or functionally analogous—sequences in other species. Isoforms are assumed to have similar functional properties, as most have similar sequences, and share some to most exons with
100-411: A single gene; post-translational modifications are generally not considered. (For that, see Proteoforms .) Through RNA splicing mechanisms, mRNA has the ability to select different protein-coding segments ( exons ) of a gene, or even different parts of exons from RNA to form different mRNA sequences. Each unique sequence produces a specific form of a protein. The discovery of isoforms could explain
120-592: Is a major molecular mechanism that may contribute to protein diversity. The spliceosome , a large ribonucleoprotein , is the molecular machine inside the nucleus responsible for RNA cleavage and ligation , removing non-protein coding segments ( introns ). Because splicing is a process that occurs between transcription and translation , its primary effects have mainly been studied through genomics techniques—for example, microarray analyses and RNA sequencing have been used to identify alternatively spliced transcripts and measure their abundances. Transcript abundance
140-543: Is an enzyme that in humans is encoded by the CPZ gene . This gene encodes a member of the metallocarboxypeptidase family. This enzyme displays carboxypeptidase activity towards substrates with basic C-terminal residues . It is most active at neutral pH and is inhibited by active site-directed inhibitors of metallocarboxypeptidases. Alternative splicing in the coding region results in multiple transcript variants encoding different isoforms . This article on
160-422: Is derived by the protein's structure/function, as well as the cell type and developmental stage during which they are produced. Determining specificity becomes more complicated when a protein has multiple subunits and each subunit has multiple isoforms. For example, the 5' AMP-activated protein kinase (AMPK), an enzyme, which performs different roles in human cells, has 3 subunits: In human skeletal muscle,
180-532: Is no conclusive evidence that it acts primarily by producing novel protein isoforms. Alternative splicing generally describes a tightly regulated process in which alternative transcripts are intentionally generated by the splicing machinery. However, such transcripts are also produced by splicing errors in a process called "noisy splicing," and are also potentially translated into protein isoforms. Although ~95% of multi-exonic genes are thought to be alternatively spliced, one study on noisy splicing observed that most of
200-543: Is often used as a proxy for the abundance of protein isoforms, though proteomics experiments using gel electrophoresis and mass spectrometry have demonstrated that the correlation between transcript and protein counts is often low, and that one protein isoform is usually dominant. One 2015 study states that the cause of this discrepancy likely occurs after translation, though the mechanism is essentially unknown. Consequently, although alternative splicing has been implicated as an important link between variation and disease, there
220-425: The abundance of mRNA transcript isoforms does not necessarily correlate with the abundance of protein isoforms. Three-dimensional protein structure comparisons can be used to help determine which, if any, isoforms represent functional protein products, and the structure of most isoforms in the human proteome has been predicted by AlphaFold and publicly released at isoform.io . The specificity of translated isoforms
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#1732779495405240-491: The canonical sequence. However, some isoforms show much greater divergence (for example, through trans-splicing ), and can share few to no exons with the canonical sequence. In addition, they can have different biological effects—for example, in an extreme case, the function of one isoform can promote cell survival, while another promotes cell death—or can have similar basic functions but differ in their sub-cellular localization. A 2016 study, however, functionally characterized all
260-486: The different low-abundance transcripts are noise, and predicts that most alternative transcript and protein isoforms present in a cell are not functionally relevant. Other transcriptional and post-transcriptional regulatory steps can also produce different protein isoforms. Variable promoter usage occurs when the transcriptional machinery of a cell ( RNA polymerase , transcription factors , and other enzymes ) begin transcription at different promoters—the region of DNA near
280-573: The discrepancy between the small number of protein coding regions of genes revealed by the human genome project and the large diversity of proteins seen in an organism: different proteins encoded by the same gene could increase the diversity of the proteome . Isoforms at the RNA level are readily characterized by cDNA transcript studies. Many human genes possess confirmed alternative splicing isoforms. It has been estimated that ~100,000 expressed sequence tags ( ESTs ) can be identified in humans. Isoforms at
300-464: The function of each isoform must generally be determined separately, most identified and predicted isoforms still have unknown functions. A glycoform is an isoform of a protein that differs only with respect to the number or type of attached glycan . Glycoproteins often consist of a number of different glycoforms, with alterations in the attached saccharide or oligosaccharide . These modifications may result from differences in biosynthesis during
320-413: The isoforms of 1,492 genes and determined that most isoforms behave as "functional alloforms." The authors came to the conclusion that isoforms behave like distinct proteins after observing that the functional of most isoforms did not overlap. Because the study was conducted on cells in vitro , it is not known if the isoforms in the expressed human proteome share these characteristics. Additionally, because
340-583: The link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=CPZ&oldid=1245224661 " Category : Disambiguation pages Hidden categories: Short description is different from Wikidata All article disambiguation pages All disambiguation pages CPZ (gene) 242939 ENSG00000109625 ENSMUSG00000036596 Q66K79 Q8R4V4 NM_003652 NM_001014447 NM_001014448 NM_153107 NP_001014447 NP_001014448 NP_003643 NP_694747 Carboxypeptidase Z
360-456: The preferred form is α2β2γ1. But in the human liver, the most abundant form is α1β2γ1. The primary mechanisms that produce protein isoforms are alternative splicing and variable promoter usage, though modifications due to genetic changes, such as mutations and polymorphisms are sometimes also considered distinct isoforms. Alternative splicing is the main post-transcriptional modification process that produces mRNA transcript isoforms, and
380-404: The process of glycosylation , or due to the action of glycosidases or glycosyltransferases . Glycoforms may be detected through detailed chemical analysis of separated glycoforms, but more conveniently detected through differential reaction with lectins , as in lectin affinity chromatography and lectin affinity electrophoresis . Typical examples of glycoproteins consisting of glycoforms are
400-407: The protein level can manifest in the deletion of whole domains or shorter loops, usually located on the surface of the protein. One single gene has the ability to produce multiple proteins that differ both in structure and composition; this process is regulated by the alternative splicing of mRNA, though it is not clear to what extent such a process affects the diversity of the human proteome, as
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