SIGNAL SEQUENCES Meaning and
Definition
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Signal sequences are short sequences of amino acids that direct newly synthesized proteins to their proper location within a cell. These sequences act as "addresses" that guide the protein to the correct compartment or organelle, ensuring its proper function and activation. Signal sequences are typically found at the N-terminus of the protein, although in some cases they may also be located at the C-terminus or within the middle of the protein.
The primary function of signal sequences is to facilitate the translocation of proteins across cellular membranes. They are recognized by specific receptor proteins located on the membrane of the target organelle. This recognition triggers a series of events that lead to the transport of the protein across the membrane and its subsequent release within the designated compartment.
Signal sequences can be categorized into different types based on their destination within the cell. For example, nuclear localization signal sequences direct proteins to the nucleus, while mitochondrial signal sequences guide proteins to mitochondria. Other signal sequences target proteins to the endoplasmic reticulum, Golgi apparatus, lysosomes, peroxisomes, or plasma membrane.
The presence of signal sequences is crucial for the proper functioning of a cell, as it ensures that proteins are correctly sorted and localized, allowing for efficient cellular processes. Mutations or abnormalities in signal sequences can lead to protein mislocalization or malfunction, which can have severe consequences on cellular physiology and human health.
Common Misspellings for SIGNAL SEQUENCES
- aignal sequences
- zignal sequences
- xignal sequences
- dignal sequences
- eignal sequences
- wignal sequences
- sugnal sequences
- sjgnal sequences
- skgnal sequences
- sognal sequences
- s9gnal sequences
- s8gnal sequences
- sifnal sequences
- sivnal sequences
- sibnal sequences
- sihnal sequences
- siynal sequences
- sitnal sequences
- sigbal sequences
- sigmal sequences
Etymology of SIGNAL SEQUENCES
The term "signal sequence" has its roots in the field of molecular biology and refers to a specific type of sequence found in proteins. In the early 1970s, scientists discovered that proteins destined for secretion or incorporation into cell membranes possess a signal sequence at the amino-terminal (N-terminal) region of the protein chain. This signal sequence acts as a "postal code" or "address label" that directs the protein to the appropriate cellular compartment.
The term "signal" reflects the role of this sequence in facilitating communication within the cell and guiding the protein to its destination. The term "sequence" refers to the specific order of amino acids in the sequence. Thus, the combination of these two words, "signal" and "sequence", give rise to the term "signal sequence", which is still widely used in the field of molecular biology to describe this phenomenon.
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