Question

your labmate is studing a mutant version of the gene KIDDO. KIDDO is an ER resident protein, but the mutant version on is found to accumulate late in the Golgi cisternae. what protion of the KIDDOA sequence do you think is mutated

Answer 1

The mutation is likely in the ER retention signal or motif of the KIDDO protein.

Step-by-step explanation:

In eukaryotic cells, proteins are synthesized in the endoplasmic reticulum (ER) and then transported to their specific cellular destinations. KIDDO is an ER resident protein, indicating it should stay within the ER. The fact that the mutant version accumulates late in the Golgi cisternae suggests a malfunction in the protein's retention signal.

Proteins contain specific signals or motifs that dictate their subcellular localization. In the case of KIDDO, there is likely a sequence that normally ensures its retention in the ER. The mutation could disrupt this signal, leading to the protein's mislocalization to the Golgi apparatus. This mislocalization could be due to the loss of an ER retention signal or the acquisition of a Golgi-targeting signal.

Understanding the specific amino acid sequence of KIDDO and comparing it with the mutant version could reveal the nature of the mutation. Researchers may focus on regions known to be involved in ER retention, such as the KDEL-like motif, and investigate if changes in these regions correlate with the observed mislocalization. Identifying the mutated portion is crucial for deciphering the underlying molecular mechanisms and developing targeted strategies to correct the protein's localization in future studies.