Journal of Cell Biology and Metabolism

All submissions of the EM system will be redirected to Online Manuscript Submission System. Authors are requested to submit articles directly to Online Manuscript Submission System of respective journal.
Reach Us +1 (202) 780-3397

Perspective - Journal of Cell Biology and Metabolism (2024) Volume 6, Issue 5

The Essential Role of Ribosomes in Cellular Biology

Xiang Zhou*

Department of Biochemistry & Molecular Biology, Tulane University School of Medicine, New Orleans, USA.

*Corresponding Author:
Xiang Zhou
Department of Biochemistry & Molecular Biology
Tulane University School of Medicine
New Orleans, USA.
E-mail: hou@tulane.edu

Received: 03-Oct-2024, Manuscript No. AACBM-24-149379; Editor assigned: 04-Oct-2024, PreQC No. AACBM-24-1493795(PQ); Reviewed: 18-Oct-2024, QC No AACBM-24-1493795; Revised: 22-Oct-2024, Manuscript No. AACBM-24-1493795(R); Published: 28-Oct-2024, DOI:10.35841/aacbm-6.5.229

Citation: Zhou X. The essential role of ribosomes in cellular biology. J Cell Biol Metab. 2024;6(5):229.

Visit for more related articles at Journal of Cell Biology and Metabolism

Abstract

  

Introduction

Ribosomes are fundamental cellular structures that play a crucial role in the process of protein synthesis, a vital function for all living organisms. By translating genetic information into functional proteins, ribosomes serve as the molecular machinery that drives cellular activities, growth, and development. Understanding ribosomes not only enhances our knowledge of cellular biology but also provides insights into medical applications and biotechnological advancements [1].

The arrangement of these sites is crucial for the ribosome's ability to facilitate the translation process efficiently. the primary function of ribosomes is to synthesize proteins through a process known as translation. This multi-step process can be divided into three main stages: initiation, elongation, and termination [2].

The initiation phase of translation begins when the small ribosomal subunit binds to the mRNA molecule. This process typically starts at the 5' cap structure in eukaryotes or at the Shine-Dalgarno sequence in prokaryotes, which helps position the ribosome correctly on the mRNA.

The initiator tRNA, carrying the amino acid methionine (in eukaryotes) or a modified form called N-formylmethionine (in prokaryotes), recognizes the start codon (AUG) on the mRNA [3].

After the initiator tRNA is positioned at the start codon, the large ribosomal subunit (60S in eukaryotes) assembles with the small subunit, forming a complete ribosome ready for elongation.

Once initiation is complete, the ribosome enters the elongation phase, which involves the sequential addition of amino acids to the growing polypeptide chain [4].

In this phase, a new aminoacyl-tRNA enters the A site. The ribosome ensures that the tRNA's anticodon matches the codon on the mRNA, a process that requires the action of elongation factors.

The ribosome catalyzes the formation of a peptide bond between the amino acid at the P site and the amino acid on the tRNA in the A site. This reaction is facilitated by the ribosomal RNA, which acts as a ribozyme [5].

After the peptide bond is formed, the ribosome undergoes a conformational change, moving the tRNA from the A site to the P site and making the A site available for the next aminoacyl-tRNA. The tRNA that was in the P site is shifted to the E site, where it will exit the ribosome.

This cycle repeats, with the ribosome moving along the mRNA, adding amino acids to the polypeptide chain until a stop codon is reached [6].

Termination occurs when the ribosome encounters a stop codon (UAA, UAG, or UGA) on the mRNA. Unlike regular codons, stop codons do not have corresponding tRNAs. Instead, release factors bind to the ribosome, triggering the release of the newly synthesized polypeptide chain from the tRNA in the P site.

Following polypeptide release, the ribosomal subunits dissociate from the mRNA and from each other, allowing them to participate in another round of translation [7].

After synthesis, many proteins undergo post-translational modifications (PTMs), such as phosphorylation, glycosylation, or methylation. These modifications can affect protein activity, localization, stability, and interactions with other molecules. Ribosomes play a role in guiding the nascent polypeptide to various cellular compartments where these modifications occur.

While the fundamental role of ribosomes is conserved across all life forms, there are significant differences between eukaryotic and prokaryotic ribosomes, which have implications for cellular processes and medical applications [8].

These ribosomes float freely in the cytoplasm and primarily synthesize proteins that function within the cytosol.

These ribosomes are attached to the endoplasmic reticulum (ER), forming rough ER. Proteins synthesized here are typically destined for secretion, incorporation into the cell membrane, or localization in organelles.

The presence of membrane-bound ribosomes allows eukaryotic cells to compartmentalize various cellular functions, enhancing efficiency and specialization [9].

Prokaryotic ribosomes, which are smaller than their eukaryotic counterparts, are typically found free-floating in the cytoplasm. Prokaryotic cells lack membrane-bound organelles, leading to a more direct relationship between transcription (the process of creating mRNA from DNA) and translation. In prokaryotes, translation can begin even before transcription is complete, allowing for rapid protein synthesis in response to environmental changes.

The structural differences between prokaryotic and eukaryotic ribosomes have significant implications for medicine, particularly in the development of antibiotics. Many antibiotics target bacterial ribosomes specifically, disrupting their ability to synthesize proteins while leaving eukaryotic ribosomes largely unaffected. This selectivity is crucial for developing effective treatments for bacterial infections [10].

References

  1. Lafontaine DL, Tollervey D. The function and synthesis of ribosomes. Nat Rev Mol Cell Biol. 2001;2(7):514-20.

    2. Indexed at, Google Scholar, Cross Ref

  2. Nomura M, Mizushima S, Ozaki M, et al. Structure and function of ribosomes and their molecular components. InCold Spring Harbor symposia on quantitative biology 1969. Cold Spring Harbor Laboratory Press.

    3. Indexed at, Google Scholar, Cross Ref

  3. Gilbert WV. Functional specialization of ribosomes?. Trends Biochem Sci. 2011;36(3):127-32.

    4. Indexed at, Google Scholar, Cross Ref

  4. Kozak M. Effects of intercistronic length on the efficiency of reinitiation by eucaryotic ribosomes. Mol Cell Biol. 1987.

    5. Indexed at, Google Scholar, Cross Ref

  5. Shine J, Dalgarno LI. Determinant of cistron specificity in bacterial ribosomes. Nature. 1975;254(5495):34-8.

    6. Indexed at, Google Scholar, Cross Ref

  6. Sulima SO, Hofman IJ, De Keersmaecker K, et al. How ribosomes translate cancer. Cancer discovery. 2017;7(10):1069-87.

    7. Indexed at, Google Scholar, Cross Ref

  7. Nierhaus KH. The assembly of prokaryotic ribosomes. Biochim. 1991;73(6):739-55.

    8. Indexed at, Google Scholar, Cross Ref

  8. Xue S, Barna M. Specialized ribosomes: a new frontier in gene regulation and organismal biology. Nat Rev Mol Cell Biol. 2012;13(6):355-69.

    9. Indexed at, Google Scholar, Cross Ref

  9. Maden BE. The structure and formation of ribosomes in animal cells. Prog Biophys. 1971;22:127-77.

    10. Indexed at, Google Scholar, Cross Ref

  10. Guo H. Specialized ribosomes and the control of translation. Biochem Soc Trans. 2018;46(4):855-69.

    11. Indexed at, Google Scholar, Cross Ref

Get the App